Update and rename hello.yml to ci.yml

Author: yongce

.github/workflows/ci.yml

@@ -0,0 +1,13 @@
+name: CI
+
+on: [push]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v1
+    - name: Build the project
+      run: ./gradlew build