remove -u on go get

appveyor.yml

@@ -21,8 +21,8 @@ install:
   - appveyor DownloadFile https://storage.googleapis.com/golang/go%GOVERSION%.windows-amd64.zip
   - 7z x go%GOVERSION%.windows-amd64.zip -y -oC:\ > NUL
   - go version
-  - go get -u v2ray.com/core/...
-  - go get -u v2ray.com/ext/...
+  - go get v2ray.com/core/...
+  - go get v2ray.com/ext/...
 
 build_script:
   - go build v2ray.com/core/main

release/release-ci.sh

@@ -32,8 +32,8 @@ export PATH=$PATH:/usr/local/go/bin
 mkdir -p /v2ray/src
 export GOPATH=/v2ray
 
-go get -u v2ray.com/core/...
-go get -u v2ray.com/ext/...
+go get v2ray.com/core/...
+go get v2ray.com/ext/...
 
 pushd $GOPATH/src/v2ray.com/core/
 git checkout tags/${RELEASE_TAG}

shippable.yml

@@ -14,6 +14,6 @@ build:
     - tar -C /usr/local -xzf golang.tar.gz
     - export PATH=$PATH:/usr/local/go/bin
     - export GOPATH=/v2ray
-    - go get -u v2ray.com/core/...
-    - go get -u v2ray.com/ext/...
+    - go get v2ray.com/core/...
+    - go get v2ray.com/ext/...
     - go test -p 1 -v v2ray.com/core/...