adds plugin verifier workflow

.github/workflows/plugin-verifier.yaml

@@ -0,0 +1,28 @@
+name: Plugin compatibility
+on:
+  - push
+  - workflow_dispatch
+jobs:
+  run:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@master
+      - name: Setup Java
+        uses: actions/setup-java@v1
+        with:
+          java-version: 11.x.x
+      - name: Build the plugin using Gradle
+        run: ./gradlew buildPlugin
+      - name: Verify Plugin on IntelliJ Platforms
+        id: verify
+        uses: ChrisCarini/intellij-platform-plugin-verifier-action@latest
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          ide-versions: |
+            ideaIC:2019.3
+            ideaIU:2019.3
+            pycharmPC:2019.3
+            goland:2019.3
+            clion:2019.3
+            ideaIC:LATEST-EAP-SNAPSHOT