Add go-licenses check to CI (#50)

Runs github.com/google/go-licenses

.github/workflows/ci.yml

@@ -20,6 +20,15 @@ jobs:
         with:
           go-version: 1.18
 
+      - name: Run go mod download
+        run: go mod download
+
+      - name: Get go-licenses
+        run: go install github.com/google/go-licenses@latest
+
+      - name: Run go-licenses
+        run: go-licenses check github.com/alcionai/corso --ignore github.com/alcionai/corso
+
       - name: Run gofmt
         run: if [ "$(gofmt -s -l . | wc -l)" -gt 0 ]; then exit 1; fi