diff --git a/Cargo.lock b/Cargo.lock
index 0d4ca33..4ee0106 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -249,41 +249,12 @@ name = "fuchsia-zircon-sys"
 version = "0.3.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
-[[package]]
-name = "futures"
-version = "0.1.29"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-
-[[package]]
-name = "futures"
-version = "0.3.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "futures-channel 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "futures-core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "futures-executor 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "futures-io 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "futures-sink 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "futures-task 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "futures-util 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
-[[package]]
-name = "futures-channel"
-version = "0.3.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "futures-core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "futures-sink 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
 [[package]]
 name = "futures-channel-preview"
 version = "0.3.0-alpha.19"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "futures-core-preview 0.3.0-alpha.19 (registry+https://github.com/rust-lang/crates.io-index)",
- "futures-sink-preview 0.3.0-alpha.19 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -296,36 +267,6 @@ name = "futures-core-preview"
 version = "0.3.0-alpha.19"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
-[[package]]
-name = "futures-executor"
-version = "0.3.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "futures-core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "futures-task 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "futures-util 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
-[[package]]
-name = "futures-executor-preview"
-version = "0.3.0-alpha.19"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "futures-core-preview 0.3.0-alpha.19 (registry+https://github.com/rust-lang/crates.io-index)",
- "futures-util-preview 0.3.0-alpha.19 (registry+https://github.com/rust-lang/crates.io-index)",
- "num_cpus 1.11.1 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
-[[package]]
-name = "futures-io"
-version = "0.3.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-
-[[package]]
-name = "futures-io-preview"
-version = "0.3.0-alpha.19"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-
 [[package]]
 name = "futures-macro"
 version = "0.3.1"
@@ -337,24 +278,6 @@ dependencies = [
  "syn 1.0.11 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
-[[package]]
-name = "futures-preview"
-version = "0.3.0-alpha.19"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "futures-channel-preview 0.3.0-alpha.19 (registry+https://github.com/rust-lang/crates.io-index)",
- "futures-core-preview 0.3.0-alpha.19 (registry+https://github.com/rust-lang/crates.io-index)",
- "futures-executor-preview 0.3.0-alpha.19 (registry+https://github.com/rust-lang/crates.io-index)",
- "futures-io-preview 0.3.0-alpha.19 (registry+https://github.com/rust-lang/crates.io-index)",
- "futures-sink-preview 0.3.0-alpha.19 (registry+https://github.com/rust-lang/crates.io-index)",
- "futures-util-preview 0.3.0-alpha.19 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
-[[package]]
-name = "futures-sink"
-version = "0.3.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-
 [[package]]
 name = "futures-sink-preview"
 version = "0.3.0-alpha.19"
@@ -370,13 +293,9 @@ name = "futures-util"
 version = "0.3.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "futures-channel 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures-core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "futures-io 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures-macro 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "futures-sink 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures-task 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "memchr 2.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "pin-utils 0.1.0-alpha.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "proc-macro-hack 0.5.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "proc-macro-nested 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -388,12 +307,9 @@ name = "futures-util-preview"
 version = "0.3.0-alpha.19"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "futures 0.1.29 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures-channel-preview 0.3.0-alpha.19 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures-core-preview 0.3.0-alpha.19 (registry+https://github.com/rust-lang/crates.io-index)",
- "futures-io-preview 0.3.0-alpha.19 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures-sink-preview 0.3.0-alpha.19 (registry+https://github.com/rust-lang/crates.io-index)",
- "memchr 2.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "pin-utils 0.1.0-alpha.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "slab 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -408,7 +324,7 @@ dependencies = [
  "futures-core-preview 0.3.0-alpha.19 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures-sink-preview 0.3.0-alpha.19 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures-util-preview 0.3.0-alpha.19 (registry+https://github.com/rust-lang/crates.io-index)",
- "http 0.1.20 (registry+https://github.com/rust-lang/crates.io-index)",
+ "http 0.1.21 (registry+https://github.com/rust-lang/crates.io-index)",
  "indexmap 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "slab 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -436,7 +352,7 @@ dependencies = [
 
 [[package]]
 name = "http"
-version = "0.1.20"
+version = "0.1.21"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "bytes 0.4.12 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -450,7 +366,7 @@ version = "0.2.0-alpha.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "bytes 0.4.12 (registry+https://github.com/rust-lang/crates.io-index)",
- "http 0.1.20 (registry+https://github.com/rust-lang/crates.io-index)",
+ "http 0.1.21 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -476,7 +392,7 @@ dependencies = [
  "futures-core-preview 0.3.0-alpha.19 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures-util-preview 0.3.0-alpha.19 (registry+https://github.com/rust-lang/crates.io-index)",
  "h2 0.2.0-alpha.3 (registry+https://github.com/rust-lang/crates.io-index)",
- "http 0.1.20 (registry+https://github.com/rust-lang/crates.io-index)",
+ "http 0.1.21 (registry+https://github.com/rust-lang/crates.io-index)",
  "http-body 0.2.0-alpha.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "httparse 1.3.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "iovec 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -816,11 +732,9 @@ dependencies = [
  "clap 2.33.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "env_logger 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "failure 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
- "futures 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "futures-preview 0.3.0-alpha.19 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures-util 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures-util-preview 0.3.0-alpha.19 (registry+https://github.com/rust-lang/crates.io-index)",
- "http 0.1.20 (registry+https://github.com/rust-lang/crates.io-index)",
+ "http 0.1.21 (registry+https://github.com/rust-lang/crates.io-index)",
  "hyper 0.13.0-alpha.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "hyper-rustls 0.19.0-alpha.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1493,19 +1407,10 @@ dependencies = [
 "checksum fnv 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)" = "2fad85553e09a6f881f739c29f0b00b0f01357c743266d478b68951ce23285f3"
 "checksum fuchsia-zircon 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "2e9763c69ebaae630ba35f74888db465e49e259ba1bc0eda7d06f4a067615d82"
 "checksum fuchsia-zircon-sys 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "3dcaa9ae7725d12cdb85b3ad99a434db70b468c09ded17e012d86b5c1010f7a7"
-"checksum futures 0.1.29 (registry+https://github.com/rust-lang/crates.io-index)" = "1b980f2816d6ee8673b6517b52cb0e808a180efc92e5c19d02cdda79066703ef"
-"checksum futures 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "b6f16056ecbb57525ff698bb955162d0cd03bee84e6241c27ff75c08d8ca5987"
-"checksum futures-channel 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "fcae98ca17d102fd8a3603727b9259fcf7fa4239b603d2142926189bc8999b86"
 "checksum futures-channel-preview 0.3.0-alpha.19 (registry+https://github.com/rust-lang/crates.io-index)" = "d5e5f4df964fa9c1c2f8bddeb5c3611631cacd93baf810fc8bb2fb4b495c263a"
 "checksum futures-core 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "79564c427afefab1dfb3298535b21eda083ef7935b4f0ecbfcb121f0aec10866"
 "checksum futures-core-preview 0.3.0-alpha.19 (registry+https://github.com/rust-lang/crates.io-index)" = "b35b6263fb1ef523c3056565fa67b1d16f0a8604ff12b11b08c25f28a734c60a"
-"checksum futures-executor 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "1e274736563f686a837a0568b478bdabfeaec2dca794b5649b04e2fe1627c231"
-"checksum futures-executor-preview 0.3.0-alpha.19 (registry+https://github.com/rust-lang/crates.io-index)" = "75236e88bd9fe88e5e8bfcd175b665d0528fe03ca4c5207fabc028c8f9d93e98"
-"checksum futures-io 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "e676577d229e70952ab25f3945795ba5b16d63ca794ca9d2c860e5595d20b5ff"
-"checksum futures-io-preview 0.3.0-alpha.19 (registry+https://github.com/rust-lang/crates.io-index)" = "f4914ae450db1921a56c91bde97a27846287d062087d4a652efc09bb3a01ebda"
 "checksum futures-macro 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "52e7c56c15537adb4f76d0b7a76ad131cb4d2f4f32d3b0bcabcbe1c7c5e87764"
-"checksum futures-preview 0.3.0-alpha.19 (registry+https://github.com/rust-lang/crates.io-index)" = "3b1dce2a0267ada5c6ff75a8ba864b4e679a9e2aa44262af7a3b5516d530d76e"
-"checksum futures-sink 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "171be33efae63c2d59e6dbba34186fe0d6394fb378069a76dfd80fdcffd43c16"
 "checksum futures-sink-preview 0.3.0-alpha.19 (registry+https://github.com/rust-lang/crates.io-index)" = "86f148ef6b69f75bb610d4f9a2336d4fc88c4b5b67129d1a340dd0fd362efeec"
 "checksum futures-task 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "0bae52d6b29cf440e298856fec3965ee6fa71b06aa7495178615953fd669e5f9"
 "checksum futures-util 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "c0d66274fb76985d3c62c886d1da7ac4c0903a8c9f754e8fe0f35a6a6cc39e76"
@@ -1513,7 +1418,7 @@ dependencies = [
 "checksum h2 0.2.0-alpha.3 (registry+https://github.com/rust-lang/crates.io-index)" = "0f107db1419ef8271686187b1a5d47c6431af4a7f4d98b495e7b7fc249bb0a78"
 "checksum heck 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)" = "20564e78d53d2bb135c343b3f47714a56af2061f1c928fdb541dc7b9fdd94205"
 "checksum hermit-abi 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "307c3c9f937f38e3534b1d6447ecf090cafcc9744e4a6360e8b037b2cf5af120"
-"checksum http 0.1.20 (registry+https://github.com/rust-lang/crates.io-index)" = "2790658cddc82e82b08e25176c431d7015a0adeb1718498715cbd20138a0bf68"
+"checksum http 0.1.21 (registry+https://github.com/rust-lang/crates.io-index)" = "d6ccf5ede3a895d8856620237b2f02972c1bbc78d2965ad7fe8838d4a0ed41f0"
 "checksum http-body 0.2.0-alpha.3 (registry+https://github.com/rust-lang/crates.io-index)" = "1f3aef6f3de2bd8585f5b366f3f550b5774500b4764d00cf00f903c95749eec3"
 "checksum httparse 1.3.4 (registry+https://github.com/rust-lang/crates.io-index)" = "cd179ae861f0c2e53da70d892f5f3029f9594be0c41dc5269cd371691b1dc2f9"
 "checksum humantime 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "df004cfca50ef23c36850aaaa59ad52cc70d0e90243c3c7737a4dd32dc7a3c4f"
diff --git a/Cargo.toml b/Cargo.toml
index 9b834fb..fbe2e6d 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -18,7 +18,6 @@ categories     = ["database"]
 log                  = "0.4"
 env_logger           = "0.7.1"
 futures-util-preview = "0.3.0-alpha.19"
-futures-preview      = { version        = "                           = 0.3.0-alpha.19", features = ["compat"] }
 clap                 = "2.33"
 serde                = "1.0"
 serde_json           = "1.0"
@@ -27,7 +26,6 @@ hyper                = { version        = "0.13.0-alpha.4" , features = ["unstab
 hyper-rustls         = { version        = "0.19.0-alpha.3" , features = [] }
 http                 = "0.1"
 num                  = "0.2"
-futures              = "0.3"
 
 [dev-dependencies]
 futures-util         = "0.3.1"