Update server dependencies

build/manifest/Gopkg.toml

@@ -1,38 +1,11 @@
-# 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]
-#   non-go = false
-#   go-tests = true
-#   unused-packages = true
-
+[prune]
+  go-tests = true
+  unused-packages = true
 
 [[constraint]]
   name = "github.com/mattermost/mattermost-server"
-  branch = "master"
+  version = "~5.3.0"
 
 [[constraint]]
   name = "github.com/pkg/errors"
   version = "0.8.0"
-
-[prune]
-  go-tests = true
-  unused-packages = true