Add build and test of micro to pre-release testing (#1684)

* fix up example test build

* build and test micro when cutting a new release

.github/workflows/micro-main.yml

@@ -0,0 +1,34 @@
+name: Build and test micro
+on:
+  push: 
+    branches:
+      - 'release-**'
+
+jobs:
+
+  build:
+    name: Build and test micro
+    runs-on: ubuntu-latest
+    steps:
+
+    - name: Set up Go 1.13
+      uses: actions/setup-go@v1
+      with:
+        go-version: 1.13
+      id: go
+
+    - name: Check out this code
+      uses: actions/checkout@v2
+      with:
+        path: 'go-micro'
+
+    - name: Check out micro
+      uses: actions/checkout@v2
+      with:
+        repository: 'micro/micro'
+        path: 'micro'
+
+    - name: Build all
+      run: $GITHUB_WORKSPACE/go-micro/.github/workflows/scripts/build-micro.sh $GITHUB_SHA
+      working-directory: micro
+    

.github/workflows/scripts/build-all-examples.sh

@@ -4,7 +4,7 @@
 function build_binary {
     echo building $1
     pushd $1
-    go build
+    go build -o _main
     local ret=$?
     if [ $ret -gt 0 ]; then 
         failed=1
@@ -32,9 +32,7 @@ function check_dir {
 }
 failed_arr=()
 failed=0
-this_hash=$1
-go mod init github.com/micro/examples
-go mod edit -require=github.com/micro/go-micro/v2@$1 
+go mod edit -replace github.com/micro/go-micro/v2=github.com/micro/go-micro/v2@$1 
 check_dir . $1
 if [ $failed -gt 0 ]; then
     echo Some builds failed

.github/workflows/scripts/build-micro.sh

@@ -0,0 +1,14 @@
+#!/bin/bash
+# set -x
+
+failed=0
+go mod edit -replace github.com/micro/go-micro/v2=github.com/micro/go-micro/v2@$1 
+# basic test, build the binary
+go build
+failed=$?
+if [ $failed -gt 0 ]; then
+    exit $failed
+fi
+# unit tests
+IN_TRAVIS_CI=yes go test -v ./...
+# TODO integration tests