Added BitBucket and GitLab CIs.

More code cleanup.

.github/workflows/gradle.yml

@@ -0,0 +1,26 @@
+name: Java CI with Gradle
+
+on:
+  push
+  pull_request
+  workflow_dispatch
+    
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Set environment variables
+      env:
+        CI_NAME: "GitHub CI"
+    - uses: actions/checkout@v2
+    - name: Set up JDK 11
+      uses: actions/setup-java@v1
+      with:
+        java-version: 11
+    - name: Grant execute permission for gradlew
+      run: chmod +x gradlew
+    - name: Test with Gradle
+      run: ./gradlew check