Adding GitHub CI workflow and badge.

Signed-off-by: Jim Hughes <[email protected]>

.github/workflows/build-and-test.yml

@@ -0,0 +1,27 @@
+name: GitHub CI
+
+on: [push, pull_request]
+
+jobs:
+  build-and-test:
+    runs-on: ubuntu-latest
+
+    steps:
+
+      - uses: actions/checkout@v2
+      - name: Set up JDK 1.8
+        uses: actions/setup-java@v1
+        with:
+          java-version: 1.8
+      - uses: actions/cache@v1
+        with:
+          path: ~/.m2/repository
+          key: ${{ runner.os }}-maven-${{ hashFiles('**/pom.xml') }}
+          restore-keys: |
+                ${{ runner.os }}-maven-
+      - name: Build with Maven
+        run: mvn clean install
+      - name: Remove JTS artifacts from cache
+        run: |
+          find . -name '*.tar.gz' -exec rm {} \;
+          rm -rf $HOME/.m2/repository/org/locationtech/jts

README.md

@@ -5,7 +5,7 @@ The JTS Topology Suite is a Java library for creating and manipulating vector ge
 
 ![JTS logo](jts_logo.png)
 
-[![Build Status](https://api.travis-ci.org/locationtech/jts.svg)](http://travis-ci.org/locationtech/jts) [![Join the chat at https://gitter.im/locationtech/jts](https://badges.gitter.im/locationtech/jts.svg)](https://gitter.im/locationtech/jts?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
+[![Travis Build Status](https://api.travis-ci.org/locationtech/jts.svg)](http://travis-ci.org/locationtech/jts) [![GitHub Action Status](https://github.com/locationtech/jts/workflows/GitHub%20CI/badge.svg)](https://github.com/locationtech/jts/actions)[![Join the chat at https://gitter.im/locationtech/jts](https://badges.gitter.im/locationtech/jts.svg)](https://gitter.im/locationtech/jts?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 
 
 JTS is a project in the [LocationTech](http://www.locationtech.org) working group of the Eclipse Foundation.