Add Github Workflow file to run tests in pre/post-submit (#116)

* add workflow file to test builds on CI

* log env variables, see if it works.

* log java home

* use set-env for environment variables.

* clean workflow file

.github/workflows/main.yml

@@ -0,0 +1,62 @@
+# Workflow to run tests
+
+name: CI
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  build-and-test:
+    strategy:
+      fail-fast: false
+
+    # The type of runner that the job will run on
+    runs-on: ubuntu-latest
+
+    steps:
+    - name: Setup Java 8
+      uses: actions/setup-java@v1.4.3
+      with:
+        java-version: '8'
+        java-package: jdk
+        architecture: x64
+    - name: set JDK 6,7,8 environment variables for kotlin compiler
+      run: echo ::set-env name=JDK_16::$(echo $JAVA_HOME) && echo ::set-env name=JDK_17::$(echo $JAVA_HOME) && echo ::set-env name=JDK_18::$(echo $JAVA_HOME)
+    - name: Setup Java 9
+      uses: actions/setup-java@v1.4.3
+      with:
+        java-version: '9'
+        java-package: jdk
+        architecture: x64
+    - name: set JDK_9 environment variable for kotlin compiler
+      run: echo ::set-env name=JDK_9::$(echo $JAVA_HOME)
+
+    # Checkout
+    - uses: actions/checkout@v2
+
+    # Build cache
+    - name: Cache Gradle Cache
+      uses: actions/cache@v2
+      with:
+        path: ~/.gradle/caches
+        key: ${{ runner.os }}-gradle-${{ hashFiles('**/*.gradle.kts') }}-${{ hashFiles('**/gradle.properties') }}
+        # An ordered list of keys to use for restoring the cache if no cache hit occurred for key
+        restore-keys: |
+          ${{ runner.os }}-gradle-
+    - name: Cache gradle wrapper
+      uses: actions/cache@v2
+      with:
+        path: ~/.gradle/wrapper
+        key: ${{ runner.os }}-gradle-wrapper-${{ hashFiles('gradle/wrapper/gradle-wrapper.properties') }}
+    # Run ksp generated tests
+    - name: test
+      run: ./gradlew --info :compiler-plugin:test --tests "com.google.devtools.ksp.test.KotlinKSPTestGenerated.*" -PcompilerTestEnabled=true
+    - name: Upload test results
+      if: always()
+      uses: actions/upload-artifact@v2
+      with:
+        name: test-reports
+        path: compiler-plugin/build/reports