ci: add unit testing step

Add step to unit test all packages in the repository. At the moment, no unit
tests exist, so tests always pass.

Signed-off-by: Victoria Dye <[email protected]>

Author: vdye

.github/workflows/main.yml

@@ -28,4 +28,7 @@ jobs:
           cd $GITHUB_WORKSPACE/src/git-bundle-server
           go vet ./...
 
-      # TODO: add automated tests.
+      - name: Run unit tests
+        run:  |
+          cd $GITHUB_WORKSPACE/src/git-bundle-server
+          go test -v ./...