Use Github Actions for CI (#442)

* Use Github Actions for CI

* Add back old Rails versions

* Only test Rails 5 on Ruby 2.7

---------

Co-authored-by: Josh Branham <josh.php@gmail.com>

.github/workflows/CI.yml

@@ -0,0 +1,40 @@
+name: CI
+
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+
+jobs:
+  test:
+    name: Ruby ${{ matrix.ruby }} / ActiveRecord ${{ matrix.active_record }}
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        active_record:
+          - '6.0'
+          - '6.1'
+          - '7.0'
+        ruby:
+          - '2.7'
+          - '3.0'
+          - '3.1'
+          - '3.2'
+        include:
+          - active_record: '5.1'
+            ruby: '2.7'
+          - active_record: '5.2'
+            ruby: '2.7'
+    env:
+      ACTIVERECORD: ${{ matrix.active_record }}
+    steps:
+    - uses: actions/checkout@v3
+    - name: Set up Ruby
+      uses: ruby/setup-ruby@v1
+      with:
+        ruby-version: ${{ matrix.ruby }}
+        bundler-cache: true
+    - run: |
+        bundle exec rake test

attr_encrypted.gemspec

@@ -29,7 +29,7 @@ Gem::Specification.new do |s|
   s.add_dependency('encryptor', ['~> 3.0.0'])
   # support for testing with specific active record version
   activerecord_version = if ENV.key?('ACTIVERECORD')
-    "~> #{ENV['ACTIVERECORD']}"
+    "~> #{ENV['ACTIVERECORD']}.0"
   else
     '>= 2.0.0'
   end