MNT Use GitHub Actions CI

.github/workflows/ci.yml

@@ -0,0 +1,13 @@
+name: CI
+
+on:
+  push:
+  pull_request:
+  workflow_dispatch:
+  # Every Saturday at 12:00pm UTC
+  schedule:
+    - cron: '0 12 * * 6'
+
+jobs:
+  ci:
+    uses: silverstripe/gha-ci/.github/workflows/ci.yml@v1

.github/workflows/keepalive.yml

@@ -0,0 +1,15 @@
+name: Keepalive
+
+on:
+  workflow_dispatch:
+  # The 4th of every month at 10:50am UTC
+  schedule:
+    - cron: '50 10 4 * *'
+
+jobs:
+  keepalive:
+    name: Keepalive
+    runs-on: ubuntu-latest
+    steps:
+      - name: Keepalive
+        uses: silverstripe/gha-keepalive@v1

readme.md

@@ -2,7 +2,7 @@
 
 Custom tag input field, for SilverStripe.
 
-[![Build Status](https://api.travis-ci.com/silverstripe/silverstripe-tagfield.svg?branch=2)](https://travis-ci.com/silverstripe/silverstripe-tagfield)
+[![CI](https://github.com/silverstripe/silverstripe-tagfield/actions/workflows/ci.yml/badge.svg)](https://github.com/silverstripe/silverstripe-tagfield/actions/workflows/ci.yml)
 [![Code Quality](http://img.shields.io/scrutinizer/g/silverstripe/silverstripe-tagfield.svg?style=flat)](https://scrutinizer-ci.com/g/silverstripe/silverstripe-tagfield)
 [![Code coverage](https://codecov.io/gh/silverstripe/silverstripe-tagfield/branch/master/graph/badge.svg)](https://codecov.io/gh/silverstripe/silverstripe-tagfield)
 [![Version](http://img.shields.io/packagist/v/silverstripe/tagfield.svg?style=flat)](https://packagist.org/packages/silverstripe/tagfield)