Upgraded to testify 1.3.0.

vendor/github.com/stretchr/testify/Gopkg.toml

@@ -1,26 +1,16 @@
-
-# Gopkg.toml example
-#
-# Refer to https://github.com/golang/dep/blob/master/docs/Gopkg.toml.md
-# for detailed Gopkg.toml documentation.
-#
-# required = ["github.com/user/thing/cmd/thing"]
-# ignored = ["github.com/user/project/pkgX", "bitbucket.org/user/project/pkgA/pkgY"]
-#
-# [[constraint]]
-#   name = "github.com/user/project"
-#   version = "1.0.0"
-#
-# [[constraint]]
-#   name = "github.com/user/project2"
-#   branch = "dev"
-#   source = "github.com/myfork/project2"
-#
-# [[override]]
-#  name = "github.com/x/y"
-#  version = "2.4.0"
-
+[prune]
+  unused-packages = true
+  non-go = true
+  go-tests = true
 
 [[constraint]]
   name = "github.com/davecgh/go-spew"
-  version = ">=1.0.0, <=3.0.0-g6d21280"
+  version = "~1.1.0"
+
+[[constraint]]
+  name = "github.com/pmezard/go-difflib"
+  version = "~1.0.0"
+
+[[constraint]]
+  name = "github.com/stretchr/objx"
+  version = "~0.1.0"