Add GH Actions for unit testing

This is the first step in moving from TravisCI to Github Actions.  So
far this will run unit tests and report to codecov.

.github/workflows/unittest.yaml

@@ -0,0 +1,36 @@
+name: unittest
+on: [push, pull_request]
+
+jobs:
+  unittest:
+    name: unittest
+    strategy:
+      matrix:
+        zk-version: [3.4.14, 3.5.6]
+        go-version: [1.11.x, 1.12.x, 1.13.x]
+    runs-on: ubuntu-latest
+    steps:
+      - name: Setup Go
+        uses: actions/setup-go@v1
+        with:
+            go-version: ${{ matrix.go-version }} 
+
+      - name: Setup Java
+        uses: actions/setup-java@v1
+        with:
+          java-version: 1.9
+
+      - name: Checkout code
+        uses: actions/checkout@v1
+
+      - name: Setup code
+        run: make setup ZK_VERSION=${{ matrix.zk-version }}
+
+      - name: Test code
+        run: make test
+
+      - name: Upload code coverage
+        uses: codecov/[email protected]
+        with:
+          token: ${{secrets.CODECOV_TOKEN}}
+          file: ./profile.cov