Added linter to github action. (#30)

* Added linter github action

* changed linter, updated setup-go version and removed unnecessary code

* added condition: on pull_request

.github/workflows/go.yml

@@ -1,13 +1,30 @@
 name: Go
-on: [push]
+on: [push, pull_request]
 jobs:
+    build:
+        name: Build
+        runs-on: ubuntu-latest
+        steps:
 
-  build:
-    name: GoCity CI
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@master
-      - uses: actions/setup-go@v1
-        with:
-          version: '1.12'
-      - run: go test -race -cover ./...
+            - name: Set up Go 1.13
+              uses: actions/setup-go@v1
+              with:
+                  go-version: 1.13
+
+            - name: Check out code into the Go module directory
+              uses: actions/checkout@v1
+              with:
+                  fetch-depth: 1
+                  path: go/src/github.com/user/gocity
+
+            - name: GolangCI-Lint
+              run: |
+                  curl -sfL https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh| sh -s v1.19.1
+                  ./bin/golangci-lint --issues-exit-code 0 run  
+              env:
+                  GOPATH: /home/runner/work/gocity/go
+            - name: Test
+              run: |
+                  go test -race -cover ./...
+              env:
+                  GOPATH: /home/runner/work/gocity/go