Remove go from the repo

Fix #1935.

.circleci/Dockerfile

@@ -1,4 +1,7 @@
 FROM circleci/android:api-28-alpha
 
-RUN sudo apt-get install -y golang
-ENV GOROOT_BOOTSTRAP /usr/lib/go
+RUN \
+	wget -O /tmp/go.tgz "https://golang.org/dl/go1.11.linux-amd64.tar.gz"; \
+	sudo tar -C /usr/local -xzf /tmp/go.tgz; \
+	rm /tmp/go.tgz
+ENV PATH /usr/local/go/bin:$PATH

.circleci/config.yml

@@ -5,15 +5,12 @@ jobs:
     docker:
       - image: shadowsocks/shadowsocks-android:circleci
     environment:
-      JVM_OPTS: -Xmx5g
-    resource_class: medium+
+      JVM_OPTS: -Xmx3.5g
     steps:
       - checkout
       - run: git submodule update --init --recursive
       - restore_cache:
           key: jars-{{ checksum "build.gradle" }}
-      - restore_cache:
-          key: go-full-{{ checksum "~/code/.git/modules/core/src/overture/go/HEAD" }}
       - run:
           name: Run Build and Tests
           command: ./gradlew assembleDebug check
@@ -22,10 +19,6 @@ jobs:
             - ~/.gradle
             - ~/.android/build-cache
           key: jars-{{ checksum "build.gradle" }}
-      - save_cache:
-          paths:
-            - ~/code/core/src/overture/go
-          key: go-full-{{ checksum "~/code/.git/modules/core/src/overture/go/HEAD" }}
       - store_artifacts:
           path: mobile/build/outputs/apk
           destination: apk/mobile

.gitmodules

@@ -30,9 +30,6 @@
 [submodule "core/src/main/jni/libev"]
 	path = core/src/main/jni/libev
 	url = https://github.com/shadowsocks/libev.git
-[submodule "core/src/overture/go"]
-	path = core/src/overture/go
-	url = https://github.com/golang/go.git
 [submodule "core/src/overture/src/github.com/shadowsocks/overture"]
 	path = core/src/overture/src/github.com/shadowsocks/overture
 	url = https://github.com/shadowsocks/overture.git

README.md

@@ -13,7 +13,7 @@ A [shadowsocks](http://shadowsocks.org) client for Android, written in Kotlin.
 ### PREREQUISITES
 
 * JDK 1.8
-* Go 1.4+
+* Go 1.11+
 * Android SDK
   - Build Tools 27+
   - Android NDK r16+
@@ -26,7 +26,6 @@ but probably painful. Further contributions regarding building on Windows are al
 
 * Set environment variable `ANDROID_HOME` to `/path/to/android-sdk`
 * (optional) Set environment variable `ANDROID_NDK_HOME` to `/path/to/android-ndk` (default: `$ANDROID_HOME/ndk-bundle`)
-* Set environment variable `GOROOT_BOOTSTRAP` to `/path/to/go`
 * Clone the repo using `git clone --recurse-submodules <repo>` or update submodules using `git submodule update --init --recursive`
 * Build it using Android Studio or gradle script
 

core/src/overture/make.bash

@@ -44,17 +44,7 @@ if [ ! -f "$ANDROID_X86_CC" ]; then
         --api $MIN_API --install-dir $ANDROID_X86_TOOLCHAIN
 fi
 
-if [ ! -f "$DIR/go/bin/go" ]; then
-    echo "Build the custom go"
-
-    pushd $DIR/go/src
-    try ./make.bash
-    popd
-fi
-
-export GOROOT=$DIR/go
 export GOPATH=$DIR
-export PATH=$GOROOT/bin:$GOPATH/bin:$PATH
 
 if [ ! -f "$TARGET/armeabi-v7a/liboverture.so" ] || [ ! -f "$TARGET/arm64-v8a/liboverture.so" ] ||
    [ ! -f "$TARGET/x86/liboverture.so" ]; then