Add GitHub Actions (#496)

* Add Github actions

Using bot's mail looks better in the wiki, since in main page it shows the pusher name but in the revisions tab it shows the bot.

Allow failure is to prevent the commit appearing with a cross just because the wiki didn't change. It can probably also be fixed in the command part, but does the same

* Rules-to-wiki 1.0

.github/workflows/build-on-pr.yml

@@ -0,0 +1,35 @@
+# This workflow will build a Java project with Gradle
+# For more information see: https://help.github.com/actions/language-and-framework-guides/building-and-testing-java-with-gradle
+
+name: Pull Request Builds
+
+on:
+  pull_request:
+    paths:
+    - "src/**"
+
+jobs:
+  Build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Set up JDK 1.8
+      uses: actions/setup-java@v1
+      with:
+        java-version: 1.8
+    - name: Cache Gradle packages
+      uses: actions/cache@v2
+      with:
+        path: ~/.gradle/caches
+        key: ${{ runner.os }}-gradle-${{ hashFiles('**/*.gradle') }}
+        restore-keys: ${{ runner.os }}-gradle
+    - name: Grant execute permission to gradlew
+      run: chmod +x gradlew
+    - name: Build with Gradle
+      run: ./gradlew build
+    - uses: actions/upload-artifact@v2
+      with:
+        name: "Compiled artifacts for Pull Request #${{github.event.number}}"
+        path: build/libs