run golangci-lint on Github Actions instead of Travis

.github/workflows/lint.yml

@@ -0,0 +1,13 @@
+on: [push, pull_request]
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: Check that no non-test files import Ginkgo or Gomega
+        run: .github/workflows/no_ginkgo.sh
+      - name: golangci-lint
+        uses: golangci/golangci-lint-action@v1
+        with:
+          # Required: the version of golangci-lint is required and must be specified without patch version: we always use the latest patch version.
+          version: v1.30

.github/workflows/no_ginkgo.sh

@@ -0,0 +1,24 @@
+#!/usr/bin/env bash
+
+# Verify that no non-test files import Ginkgo or Gomega.
+
+set -e
+
+HAS_TESTING=false
+
+cd ..
+for f in $(find . -name "*.go" ! -name "*_test.go"); do
+	if grep -q "github.com/onsi/ginkgo" $f; then
+    echo "$f imports github.com/onsi/ginkgo"
+    HAS_TESTING=true
+	fi
+	if grep -q "github.com/onsi/gomega" $f; then
+    echo "$f imports github.com/onsi/gomega"
+    HAS_TESTING=true
+	fi
+done
+
+if "$HAS_TESTING"; then
+	exit 1
+fi
+exit 0