migrate Gopkg.toml and Gopkg.lock to new format

Update Gopkg.toml and Gopkg.lock to follow the breaking changes
introduced by golang/dep#644

Gopkg.toml

@@ -14,7 +14,7 @@
 
 ## Dependencies define constraints on dependent projects. They are respected by
 ## dep whether coming from the Gopkg.toml of the current project or a dependency.
-# [[dependencies]]
+# [[constraint]]
 ## Required: the root import path of the project being constrained.
 # name = "github.com/user/project"
 #
@@ -27,12 +27,12 @@
 ## Optional: an alternate location (URL or import path) for the project's source.
 # source = "https://github.com/myfork/package.git"
 
-## Overrides have the same structure as [[dependencies]], but supercede all
-## [[dependencies]] declarations from all projects. Only the current project's
-## [[overrides]] are applied.
+## Overrides have the same structure as [[constraint]], but supercede all
+## [[constraint]] declarations from all projects. Only the current project's
+## [[override]] are applied.
 ##
 ## Overrides are a sledgehammer. Use them only as a last resort.
-# [[overrides]]
+# [[override]]
 ## Required: the root import path of the project being constrained.
 # name = "github.com/user/project"
 #
@@ -51,90 +51,90 @@
 
 
 
-[[dependencies]]
+[[constraint]]
   branch = "master"
   name = "bazil.org/fuse"
 
-[[dependencies]]
+[[constraint]]
   branch = "master"
   name = "github.com/Unknwon/goconfig"
 
-[[dependencies]]
+[[constraint]]
   branch = "master"
   name = "github.com/VividCortex/ewma"
 
-[[dependencies]]
+[[constraint]]
   branch = "master"
   name = "github.com/aws/aws-sdk-go"
 
-[[dependencies]]
+[[constraint]]
   branch = "master"
   name = "github.com/ncw/go-acd"
 
-[[dependencies]]
+[[constraint]]
   branch = "master"
   name = "github.com/ncw/swift"
 
-[[dependencies]]
+[[constraint]]
   branch = "master"
   name = "github.com/pkg/errors"
 
-[[dependencies]]
+[[constraint]]
   branch = "master"
   name = "github.com/pkg/sftp"
 
-[[dependencies]]
+[[constraint]]
   branch = "master"
   name = "github.com/rfjakob/eme"
 
-[[dependencies]]
+[[constraint]]
   branch = "master"
   name = "github.com/skratchdot/open-golang"
 
-[[dependencies]]
+[[constraint]]
   branch = "master"
   name = "github.com/spf13/cobra"
 
-[[dependencies]]
+[[constraint]]
   branch = "master"
   name = "github.com/spf13/pflag"
 
-[[dependencies]]
+[[constraint]]
   branch = "master"
   name = "github.com/stacktic/dropbox"
 
-[[dependencies]]
+[[constraint]]
   branch = "master"
   name = "github.com/stretchr/testify"
 
-[[dependencies]]
+[[constraint]]
   branch = "master"
   name = "github.com/tsenart/tb"
 
-[[dependencies]]
+[[constraint]]
   branch = "master"
   name = "golang.org/x/crypto"
 
-[[dependencies]]
+[[constraint]]
   branch = "master"
   name = "golang.org/x/net"
 
-[[dependencies]]
+[[constraint]]
   branch = "master"
   name = "golang.org/x/oauth2"
 
-[[dependencies]]
+[[constraint]]
   branch = "master"
   name = "golang.org/x/sys"
 
-[[dependencies]]
+[[constraint]]
   branch = "master"
   name = "golang.org/x/text"
 
-[[dependencies]]
+[[constraint]]
   branch = "master"
   name = "google.golang.org/api"
 
-[[dependencies]]
+[[constraint]]
   branch = "master"
   name = "github.com/ncw/dropbox-sdk-go-unofficial"