👷 Adding ci github action

Author: langecode

.github/workflows/ci.yaml

@@ -0,0 +1,18 @@
+name: ci
+
+on: [push]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        java: [ 8, 12, 15 ]
+    steps:
+      - uses: actions/checkout@v2
+      - name: Set Java
+        uses: actions/setup-java@v1
+        with:
+          java-version: ${{ matrix.java }}
+      - name: Build with Maven
+        run: mvn --batch-mode --update-snapshots verify -Dgpg.skip=true