Add ability to download GitWave.zip for GitHub action

Author: introfog

.github/workflows/maven.yml

@@ -19,3 +19,9 @@ jobs:
         cache: maven
     - name: Build with Maven
       run: mvn clean package
+    - name: Upload Artifact
+      uses: actions/upload-artifact@v2
+      with:
+        name: GitWave
+        path: target/GitWave.zip
+