Switch protobuf generation to buf cli tool

Current generation of protobuf stubs is hard and there's open issues
around it:
   grpc-ecosystem/grpc-gateway#1065

grpc-gateway author and README suggest to use `buf` instead which
intends to be a simpler and more reliable method of protobuf stub
generation.

engine/rpcserver.go

@@ -16,7 +16,7 @@ import (
 
 	"github.com/gofrs/uuid"
 	grpcauth "github.com/grpc-ecosystem/go-grpc-middleware/auth"
-	"github.com/grpc-ecosystem/grpc-gateway/v2/runtime"
+	"github.com/grpc-ecosystem/grpc-gateway/runtime"
 	"github.com/thrasher-corp/gocryptotrader/common"
 	"github.com/thrasher-corp/gocryptotrader/common/crypto"
 	"github.com/thrasher-corp/gocryptotrader/common/file"

gctrpc/README.md

@@ -27,39 +27,12 @@ be toggled on or off depending on the users preference.
 
 ## Installation
 
-GoCryptoTrader requires a local installation of the Google protocol buffers
-compiler `protoc` v3.0.0 or above. Please install this via your local package
-manager or by downloading one of the releases from the official repository:
+GoCryptoTrader requires a local installation of the `buf` cli tool that tries to make Protobuf handling more easier and reliable,
+after [installation](https://docs.buf.build/installation) you'll need to run:
 
-[protoc releases](https://github.com/protocolbuffers/protobuf/releases)
+$ buf beta mod update
 
-Then use `go get` to download the following packages:
+After previous command, make necessary changes to the `rpc.proto` spec file and run the generation command:
 
-```bash
-go get github.com/grpc-ecosystem/grpc-gateway/v2/protoc-gen-grpc-gateway
-go get github.com/grpc-ecosystem/grpc-gateway/protoc-gen-swagger
-go get google.golang.org/protobuf/cmd/protoc-gen-go
-go get google.golang.org/grpc/cmd/protoc-gen-go-grpc
-```
+$ buf generate
 
-This will place three binaries in your `$GOBIN`;
-
-* `protoc-gen-grpc-gateway`
-* `protoc-gen-swagger`
-* `protoc-gen-go`
-* `protoc-gen-go-grpc`
-
-Make sure that your `$GOBIN` is in your `$PATH`.
-
-## Usage
-
-After the above dependencies are required, make necessary changes to the `rpc.proto`
-spec file and run the generation scripts:
-
-### Windows
-
-Run `gen_pb_win.bat`
-
-### Linux and macOS
-
-Run `./gen_pb_linux.sh`

gctrpc/buf.gen.yaml

@@ -0,0 +1,15 @@
+version: v1beta1
+plugins:
+  - name: go
+    out: ./
+    opt:
+      - paths=source_relative
+  - name: go-grpc 
+    out: ./
+    opt:
+      - paths=source_relative
+  - name: grpc-gateway
+    out: ./
+    opt:
+      - paths=source_relative
+      - generate_unbound_methods=true

gctrpc/buf.lock

@@ -0,0 +1,17 @@
+# Generated by buf. DO NOT EDIT.
+version: v1
+deps:
+  - remote: buf.build
+    owner: beta
+    repository: googleapis
+    branch: main
+    commit: 1c473ad9220a49bca9320f4cc690eba5
+    digest: b1-unlhrcI3tnJd0JEGuOb692LZ_tY_gCGq6mK1bgCn1Pg=
+    create_time: 2021-06-23T20:16:47.788079Z
+  - remote: buf.build
+    owner: grpc-ecosystem
+    repository: grpc-gateway
+    branch: main
+    commit: d19475fa22444a289c46af009acce62c
+    digest: b1-_zhDPyr_Ctc1QRAKuad6_0xvoyPd6QaB22ldm9gzS0Q=
+    create_time: 2021-04-26T15:19:26.742789Z

gctrpc/buf.yaml

@@ -0,0 +1,5 @@
+version: v1beta1
+name: buf.build/gocryptotrader/grpc
+deps:
+  - buf.build/beta/googleapis
+  - buf.build/grpc-ecosystem/grpc-gateway

go.mod

@@ -12,6 +12,7 @@ require (
 	github.com/gorilla/mux v1.8.0
 	github.com/gorilla/websocket v1.4.2
 	github.com/grpc-ecosystem/go-grpc-middleware v1.3.0
+	github.com/grpc-ecosystem/grpc-gateway v1.16.0 // indirect
 	github.com/grpc-ecosystem/grpc-gateway/v2 v2.5.0
 	github.com/kat-co/vala v0.0.0-20170210184112-42e1d8b61f12
 	github.com/kr/text v0.2.0 // indirect