Add github actions for running specs

This adds the github actions and badge for showing tests are working (or
not ;)

.github/workflows/ci.yml

@@ -0,0 +1,29 @@
+---
+name: CI
+
+on:
+  pull_request:
+    branches:
+      - '*'
+  push:
+    branches:
+      - master
+jobs:
+  # SQLITE
+  testrunner:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        ruby: ['2.7', '3.0', '3.1']
+
+    steps:
+      - uses: actions/checkout@v2
+      - name: Set up Ruby ${{ matrix.ruby }}
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: ${{ matrix.ruby }}
+          bundler-cache: true
+
+      - name: Run tests
+        run: |
+          bundle exec rspec spec

README.md

@@ -1,5 +1,5 @@
 # VimwikiMarkdown
-[![Code Climate](https://codeclimate.com/github/patrickdavey/vimwiki_markdown/badges/gpa.svg)](https://codeclimate.com/github/patrickdavey/vimwiki_markdown)
+[![Code Climate](https://codeclimate.com/github/patrickdavey/vimwiki_markdown/badges/gpa.svg)](https://codeclimate.com/github/patrickdavey/vimwiki_markdown) ![CI Status](https://github.com/patrickdavey/vimwiki_markdown/actions/workflows/ci.yml/badge.svg)
 
 This gem allows vimwiki pages written in (github enhanced) markdown
 to be converted to HTML.