Add Github Actions

.github/workflows/maven.yml

@@ -0,0 +1,32 @@
+name: Java CI
+
+on: [push, pull_request]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Set up JDK 8
+      uses: actions/setup-java@v1.3.0
+      with:
+        java-version: 8
+    - uses: actions/cache@v1.1.2
+      with:
+        path: ~/.m2/repository
+        key: ${{ runner.os }}-maven-${{ hashFiles('**/pom.xml') }}
+        restore-keys: |
+          ${{ runner.os }}-maven-
+    - name: Patch
+      run: |
+        git config --global user.email "you@example.com"
+        git config --global user.name "Your Name"
+        git submodule update --init --recursive
+        ./akarin jar
+    - name: Upload Artifact
+      uses: actions/upload-artifact@v2-preview
+      with:
+        path: akarin-paperclip.jar
+