Add GitHub Actions CI for pull request testing

.github/workflows/gradle.yml

@@ -1,23 +1,51 @@
-name: Java CI
-
-on: [push]
+name: CI
 
+on:
+  push:
+    branches:
+      - '*'
+  pull_request:
+    branches:
+      - '*'
 jobs:
-  build:
-    
+  windows:
+    name: Windows (Java 11)
     runs-on: windows-latest
+    steps:
+    - uses: actions/checkout@v2
+      with:
+        fetch-depth: 10
+    - name: Set up JDK 11
+      uses: actions/setup-java@v1
+      with:
+        java-version: 11
+    - name: Build
+      run: ./gradlew build
 
+  linux:
+    name: Linux (Java 8)
+    runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v1
-    - name: Set up JDK 1.11
+    - uses: actions/checkout@v2
+      with:
+        fetch-depth: 10
+    - name: Set up JDK 8
+      uses: actions/setup-java@v1
+      with:
+        java-version: 8
+    - name: Build
+      run: ./gradlew build
+
+  macos:
+    name: macOS (Java 11)
+    runs-on: macos-latest
+    steps:
+    - uses: actions/checkout@v2
+      with:
+        fetch-depth: 10
+    - name: Set up JDK 11
       uses: actions/setup-java@v1
       with:
-        java-version: 1.11
-    - name: Build with Gradle
-      env:
-        repoUrl : '${{secrets.deployRepoUrl}}'
-        repoUsername : '${{secrets.deployRepoUsername}}'
-        repoPassword : '${{secrets.deployRepoPassword}}'
-        signPassword : '${{secrets.SIGNING_PASSWORD}}'
-        signKey : '${{secrets.SIGNING_KEY}}'
-      run: ./gradlew build -PdeployRepoUrlProp='${{secrets.deployRepoUrl}}' -PdeployRepoUsernameProp='${{secrets.deployRepoUsername}}' -PdeployRepoPasswordProp='${{secrets.deployRepoPassword}}' -PsigningPasswordProp='${{secrets.SIGNING_PASSWORD}}' -PsigningKeyProp='${{secrets.SIGNING_KEY}}'
+        java-version: 11
+    - name: Build
+      run: ./gradlew build

README.md

@@ -1,5 +1,6 @@
 # Darklaf - A Darcula Look and Feel
 
+[![CI Status](https://github.com/weisJ/darklaf/workflows/CI/badge.svg?branch=master)](https://github.com/weisJ/darklaf/actions)
 [![Maven Central](https://img.shields.io/maven-central/v/com.github.weisj/darklaf.svg?label=Maven%20Central)](https://search.maven.org/search?q=g:%22com.github.weisj%22%20AND%20a:%22darklaf%22)
 
 This project is based on the [darcula](https://github.com/bulenkov/Darcula) look and feel for Swing.