add ci action workflow (#50)

add action workflow

We should keep following actions/setup-go#12 to reduce custom GOPATH configs and PATH adjustments.

.github/workflows/push.yml

@@ -0,0 +1,46 @@
+name: Go
+on: [push]
+jobs:
+
+  build:
+    name: Build
+    runs-on: ubuntu-latest
+    steps:
+
+    - name: Set up Go 1.12
+      uses: actions/setup-go@v1
+      with:
+        go-version: 1.12
+      id: go
+
+    - name: Check out code into the Go module directory
+      uses: actions/checkout@v1
+      with:
+        fetch-depth: 1
+        path: go/src/github.com/gesellix/couchdb-prometheus-exporter
+
+    - name: Get dependencies
+      run: |
+        mkdir -p $GOPATH/bin
+        export PATH=$PATH:$GOPATH/bin
+        go get -v -t -d ./...
+        if [ -f Gopkg.toml ]; then
+            curl https://raw.githubusercontent.com/golang/dep/master/install.sh | sh
+            dep ensure
+        fi
+      env:
+        GOPATH: /home/runner/work/couchdb-prometheus-exporter/go
+
+    - name: Check
+      run: |
+        cd $GOPATH/src/github.com/gesellix/couchdb-prometheus-exporter
+        ./integrationtest-setup.sh
+        go test -v ./...
+        ./integrationtest-teardown.sh
+      env:
+        GOPATH: /home/runner/work/couchdb-prometheus-exporter/go
+
+    - name: Build
+      run: go build -v ./...
+      env:
+        GOPATH: /home/runner/work/couchdb-prometheus-exporter/go