[Build] Migrate to GitHub actions

.github/workflows/ci-build.yml

@@ -0,0 +1,13 @@
+name: CI Build
+on: [ push, pull_request ]
+jobs:
+  gradle:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-java@v1
+        with:
+          java-version: 8
+      - uses: eskatos/gradle-command-action@v1
+        with:
+          arguments: build

.travis.yml

@@ -1,16 +0,0 @@
-language: java
-os: linux
-sudo: false
-
-before_install:
-  - chmod +x gradlew
-  - chmod +x gradle/wrapper/gradle-wrapper.jar
-
-before_cache:
-  - rm -f  $HOME/.gradle/caches/modules-2/modules-2.lock
-  - rm -fr $HOME/.gradle/caches/*/plugin-resolution/
-
-cache:
-  directories:
-    - $HOME/.gradle/caches/
-    - $HOME/.gradle/wrapper/