Updating to github actions

 - testing the PR build
 - testing and releasing an exp version of the jar via Java 15
 - making a stable release

Also updated the plugin version nd the min GoCD version to 20.9.0

Author: kritika-singh3

.github/workflows/pr_workflow.yml

@@ -0,0 +1,21 @@
+# 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: Testing For PRs
+
+on: [ pull_request ]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - name: Set up JDK
+      uses: actions/setup-java@v1
+      with:
+        java-version: 15
+    - name: Echo env
+      run: env
+      shell: bash
+    - name: Build with Gradle
+      run: ./gradlew assemble check

.github/workflows/release.yml

@@ -0,0 +1,31 @@
+
+name: Create Stable Release
+
+# Controls when the action will run. Workflow runs when manually triggered using the UI
+# or API.
+on:
+  workflow_dispatch:
+    # Inputs the workflow accepts.
+    inputs:
+      prerelease:
+        description: 'The release should be an experimental release'
+        default: 'NO'
+        required: true
+
+jobs:
+  build_and_release:
+    runs-on: ubuntu-latest
+    env:
+      GITHUB_USER:  "gocd-contrib"
+      GITHUB_TOKEN: "${{ secrets.GITHUB_TOKEN }}"
+      PRERELEASE:   "${{ github.event.inputs.prerelease }}"
+    steps:
+    - uses: actions/checkout@v2
+      with:
+        fetch-depth: 0
+    - name: Set up JDK
+      uses: actions/setup-java@v1
+      with:
+        java-version: 15
+    - name: Release
+      run: ./gradlew githubRelease

.github/workflows/test_and_build.yml

@@ -0,0 +1,36 @@
+# 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: Test and Build
+
+on:
+  push:
+    branches: [ master ]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - name: Set up JDK
+      uses: actions/setup-java@v1
+      with:
+        java-version: 15
+    - name: Test with Gradle
+      run: ./gradlew assemble check
+  previewGithubRelease:
+    needs: test
+    runs-on: ubuntu-latest
+    env:
+      GITHUB_USER:  "gocd-contrib"
+      GITHUB_TOKEN: "${{ secrets.GITHUB_TOKEN }}"
+    steps:
+    - uses: actions/checkout@v2
+      with:
+        fetch-depth: 0
+    - name: Set up JDK
+      uses: actions/setup-java@v1
+      with:
+        java-version: 15
+    - name: Test with Gradle
+      run: ./gradlew githubRelease

build.gradle

@@ -19,8 +19,8 @@ apply from: "https://raw.githubusercontent.com/gocd/gocd-plugin-gradle-task-help
 
 gocdPlugin {
   id = 'cd.go.authorization.github'
-  pluginVersion = '3.0.2'
-  goCdVersion = '19.2.0'
+  pluginVersion = '3.1.0'
+  goCdVersion = '20.9.0'
   name = 'GitHub OAuth authorization plugin'
   description = 'GitHub OAuth authorization plugin for GoCD'
   vendorName = 'ThoughtWorks, Inc.'