Add monkey dependency & cleanup dep file

Gopkg.lock

@@ -1,6 +1,12 @@
 # This file is autogenerated, do not edit; changes may be undone by the next 'dep ensure'.
 
 
+[[projects]]
+  branch = "master"
+  name = "github.com/bouk/monkey"
+  packages = ["."]
+  revision = "b96e337f6e5b36906584cd0cf9803bbab09284f7"
+
 [[projects]]
   name = "github.com/davecgh/go-spew"
   packages = ["spew"]
@@ -122,6 +128,6 @@
 [solve-meta]
   analyzer-name = "dep"
   analyzer-version = 1
-  inputs-digest = "51b1b1e1478f8646b2d5bc041005b561d738cff03a01582136d7acfb5e3bcf13"
+  inputs-digest = "37f49452e577dec701b2616f145ad6018a8408c6cc63c29a72a8bf1e889d3a4a"
   solver-name = "gps-cdcl"
   solver-version = 1

Gopkg.toml

@@ -19,14 +19,9 @@
 #  name = "github.com/x/y"
 #  version = "2.4.0"
 
-ignored = ["golang.org/x/tools/go/gcimporter15/testdata"]
 [[constraint]]
   name = "github.com/gin-gonic/gin"
   branch = "master"
 
-[[constraint]]
-  name = "gopkg.in/go-playground/validator.v8"
-  version = "8.18.2"
-
 [prune]
   unused-packages = true