GitHub actions to replace Travis

.github/workflows/ci.yml

@@ -0,0 +1,32 @@
+name: CI
+
+on:
+  pull_request:
+  push:
+    branches:
+      - master
+      - main
+    tags-ignore:
+      - v*
+
+jobs:
+  build:
+    name: Code Style, Tests, Documentation
+    runs-on: ubuntu-20.04
+    env:
+      JAVA_OPTS: -Xms2G -Xmx2G -Xss2M -XX:ReservedCodeCacheSize=256M -Dfile.encoding=UTF-8
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+
+      - name: Set up JDK 11
+        uses: coursier/[email protected]
+        with:
+          jvm: adopt:11
+
+      - name: Cache Coursier cache
+        uses: coursier/[email protected]
+
+      - name: "Code style, tests, documentation"
+        run: sbt "scalafmtCheckAll; scalafmtSbtCheck; test; doc"

CONTRIBUTING.md

@@ -6,7 +6,7 @@ In case of questions about the contribution process or for discussion of specifi
 
 * [Lightbend Contributor License Agreement](http://www.lightbend.com/contribute/cla)
 * [Issue Tracker](https://github.com/akka/akka-stream-contrib/issues)
-* [CI](https://travis-ci.org/akka/akka-stream-contrib)
+* [CI on GitHub actions](https://github.com/akka/akka-stream-contrib/actions)
 
 # Lightbend Project & Developer Guidelines
 
@@ -133,9 +133,5 @@ Example:
 ## How To Enforce These Guidelines?
 
 ### Make Use of Pull Request Validator
-akka-stream-contrib uses [Travis pull request builder](https://travis-ci.org/akka/akka-stream-contrib)
+akka-stream-contrib uses [GitHub actions](https://github.com/akka/akka-stream-contrib/actions)
 that automatically merges the code, builds it, runs the tests and comments on the Pull Request in GitHub.
-
-## Source style
-
-akka-stream-contrib uses [Scalariform](https://github.com/daniel-trinh/scalariform) to enforce some of the code style rules.