Add the release CI setting

Author: civitaspo

.github/FUNDING.yml

@@ -0,0 +1 @@
+github: civitaspo

.github/workflows/release.yml

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+name: Release CI
+
+on:
+  push:
+    tags:
+      - '*'
+
+jobs:
+  release:
+
+    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: Release the new gem
+      run: |
+        mkdir -p $HOME/.gem
+        touch $HOME/.gem/credentials
+        chmod 0600 $HOME/.gem/credentials
+        printf -- "---\n:rubygems_api_key: ${RUBYGEMS_API_KEY}\n" > $HOME/.gem/credentials
+        ./gradlew gemPush
+      env:
+        RUBYGEMS_API_KEY: ${{secrets.RUBYGEMS_API_KEY}}