Drop ruby 2.x support (#139)

Nokogiri requires 3.x so we need to upgrade our limitations.

Ruby 2 is also past end of life, so there's no reason to continue supporting it.

Author: marcqualie

.github/workflows/test.yml

@@ -12,8 +12,7 @@ jobs:
     strategy:
       matrix:
         ruby:
-          - "2.7.5"
-          - "3.0.3"
+          - "3.0.6"
     steps:
     - uses: actions/checkout@v2
     - name: Set up Ruby
@@ -23,12 +22,13 @@ jobs:
         bundler-cache: true
     - name: Run rspec
       run: bundle exec rake test
+
   rubocop:
     runs-on: ubuntu-latest
     strategy:
       matrix:
         ruby:
-          - "2.7.5"
+          - "3.0.6"
     steps:
     - uses: actions/checkout@v2
     - name: Set up Ruby

test/rails_test.rb

@@ -6,9 +6,9 @@
 require 'open3'
 
 RAILS_VERSIONS = %w[
-  6.0.4.4
-  6.1.4.4
-  7.0.1
+  6.0.6.1
+  6.1.7.6
+  7.0.8
 ].freeze
 
 RAILS_FLAGS = %w[