Add Test Github Action

.github/workflows/test.yml

@@ -0,0 +1,18 @@
+on: [push, pull_request]
+name: Test
+jobs:
+  test:
+    strategy:
+      matrix:
+        go-version: [1.15.x, 1.16.x]
+        os: [ubuntu-latest, macos-latest, windows-latest]
+    runs-on: ${{ matrix.os }}
+    steps:
+    - name: Install Go
+      uses: actions/setup-go@v2
+      with:
+        go-version: ${{ matrix.go-version }}
+    - name: Checkout code
+      uses: actions/checkout@v2
+    - name: Test
+      run: go test ./...

README.md

@@ -1,6 +1,6 @@
 # go-pcre
 
-[![GoDoc](https://godoc.org/github.com/gijsbers/go-pcre?status.svg=)](https://pkg.go.dev/github.com/scorpionknifes/go-pcre)
+[![GoDoc](https://godoc.org/github.com/gijsbers/go-pcre?status.svg=)](https://pkg.go.dev/github.com/scorpionknifes/go-pcre) [![Test](https://github.com/scorpionknifes/go-pcre/actions/workflows/test.yml/badge.svg)](https://github.com/scorpionknifes/go-pcre/actions/workflows/test.yml)
 
 This is a Go language package providing support for Perl Compatible Regular Expressions (PCRE).