Replace Travis CI with GitHub Actions for testing main branch and PRs

.github/workflows/test.yml

@@ -0,0 +1,22 @@
+name: Linux build
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Set up JDK 11
+      uses: actions/setup-java@v2
+      with:
+        java-version: '11'
+        distribution: 'adopt'
+    - name: Run tests
+      run: sbt test

README.md

@@ -1,7 +1,7 @@
 [![Maven Central](https://img.shields.io/maven-central/v/dev.dirs/directories.svg)](https://search.maven.org/#search|gav|1|g%3A%22dev.dirs%22%20AND%20a%3A%22directories%22)
 [![API documentation](http://javadoc.io/badge/dev.dirs/directories.svg)](http://javadoc.io/doc/dev.dirs/directories)
 ![actively developed](https://img.shields.io/badge/maintenance-actively_developed-brightgreen.svg)
-[![TravisCI status](https://img.shields.io/travis/dirs-dev/directories-jvm/main.svg?label=Linux%20build)](https://travis-ci.org/dirs-dev/directories-jvm)
+[![GitHub Actions status](https://github.com/dirs-dev/directories-jvm/workflows/Linux%20build/badge.svg)](https://github.com/dirs-dev/directories-jvm/actions/workflows/test.yml)
 [![AppVeyor status](https://img.shields.io/appveyor/ci/soc/directories-jvm/main.svg?label=Windows%20build)](https://ci.appveyor.com/project/soc/directories-jvm/branch/main)
 [![License: MPL-2.0](https://img.shields.io/github/license/dirs-dev/directories-jvm.svg)](LICENSE)