Merge pull request #21 from fritjof-b/master

Added simple CI using GH actions and build status to readme, fix #19

.github/workflows/main.yml

@@ -0,0 +1,11 @@
+name: Build
+on: [push]
+jobs:
+  Test:
+    runs-on: ubuntu-20.04
+    steps:
+      - name: Check out repository code
+        uses: actions/checkout@v2
+      - name: SBT Build
+        run: sbt compile
+        shell: bash

README.md

@@ -1,5 +1,7 @@
 # introprog-scalalib
 
+![Build Status](https://github.com/lunduniversity/introprog-scalalib/actions/workflows/main.yml/badge.svg)
+
 [<img src="https://img.shields.io/maven-central/v/se.lth.cs/introprog_3.svg?label=latest%20release%20for%20Scala%203">](http://search.maven.org/#search%7Cga%7C1%7Cg%3Ase.lth.cs%20a%3Aintroprog_3)  [<img src="https://img.shields.io/maven-central/v/se.lth.cs/introprog_2.13.svg?label=latest%20release%20for%202.13">](http://search.maven.org/#search%7Cga%7C1%7Cg%3Ase.lth.cs%20a%3Aintroprog_2.13)  [<img src="https://img.shields.io/maven-central/v/se.lth.cs/introprog_2.12.svg?label=latest%20release%20for%202.12">](http://search.maven.org/#search%7Cga%7C1%7Cg%3Ase.lth.cs%20a%3Aintroprog_2.12)
 
 This is a library with Scala utilities for Computer Science teaching. The library is maintained by Björn Regnell at Lund University, Sweden. Contributions are welcome!