Cleanup Sonar issues, added Github build and formatted source

.github/workflows/maven.yml

@@ -0,0 +1,37 @@
+name: Java Maven Build
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Checkout source
+      uses: actions/checkout@v2
+
+    - name: Show versions
+      run: ./mvnw -version
+
+    - name: Set up JDK 11
+      uses: actions/setup-java@v2
+      with:
+        java-version: '11'
+        distribution: 'zulu'
+        cache: maven
+
+    - name: Cache Maven packages
+      uses: actions/cache@v1
+      with:
+        path: ~/.m2
+        key: ${{ runner.os }}-m2-${{ hashFiles('**/pom.xml') }}
+        restore-keys: ${{ runner.os }}-m2
+
+    - name: Build with Maven
+      run: ./mvnw clean verify -U -B --file pom.xml
+