Added Github Actions

.github/workflows/maven.yml

@@ -0,0 +1,40 @@
+name: Maven Build
+
+on: [push, pull_request]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Checkout Repository
+      uses: actions/checkout@v2
+    
+    - name: Set up JDK 16
+      uses: actions/setup-java@v2
+      with:
+        java-version: 16
+        distribution: 'adopt'
+
+    - name: Cache Maven packages
+      uses: actions/cache@v2.1.5
+      with:
+        path: ~/.m2
+        key: ${{ runner.os }}-m2-${{ hashFiles('**/pom.xml') }}
+        restore-keys: ${{ runner.os }}-m2
+
+    - name: Build with Maven
+      uses: nick-invision/retry@v2
+      with:
+        timeout_minutes: 5
+        max_attempts: 3
+        command: mvn -B package --file pom.xml
+    
+    - name: Upload artifact
+      uses: actions/upload-artifact@v2.2.3
+      with:
+        name: AuthmeVelocity
+        path: |
+          proxy/target/AuthMeVelocity-proxy.jar
+          spigot/target/AuthMeVelocity-spigot.jar