Fix #202 auto publish the release to bintray using github actions

- Username and api key comes from secret

Author: arulrajnet

.github/workflows/publish.yml

@@ -0,0 +1,21 @@
+name: Publish Bintray
+on:
+  release:
+    types: [published]
+
+jobs:
+  publish:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v1
+    - name: Set up JDK 1.8
+      uses: actions/setup-java@v1
+      with:
+        java-version: 1.8
+    - name: Grant Permission to Execute
+      run: chmod +x gradlew
+    - name: Publish Library
+      env:
+        BINTRAY_USERNAME: ${{ secrets.BINTRAY_USERNAME }}
+        BINTRAY_API_KEY: ${{ secrets.BINTRAY_API_KEY }}
+      run: ./gradlew bintrayUpload