Add Go linting to the client.yml workflow

As part of work on RFC-18 a job linting the Go code has been added to
`client.yml` workflow. Action for linting of Go code has been also added
(as separate repository) as part of this work.

Author: michalinacienciala

.github/workflows/client.yml

@@ -38,4 +38,12 @@ jobs:
       - uses: actions/checkout@v2
       - uses: securego/gosec@master
         with:
-          args: ./...
+          args: ./...
+
+  client-lint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Lint Go
+        uses: keep-network/golint-action@v1.0.2