Add Ruby 3.1 to CI (#558)

* Add Ruby 3.1 to CI

Update Rubocop for recent Rubies
Disable Rubocop run for Rubies before Ruby 2.4
Quote '3.0' in the CI configuration to ensure it loads a 3.0.x Ruby
Set RUBYOPT="--disable_error_highlight" so Ruby 3.1 error matchers pass

* Add CHANGELOG.md entry

* Re-add deleted line from CHANGELOG.md

* Set minimum supported Ruby version to 2.4.

Remove a number of code bits designed to support Rubies below version 2.4

* Bump version.  Remove unneeded require from Gemfile.  Add require to spec/support file

1 files changed, 15 insertions, 17 deletions

diff --git a/spec/hashie/array_spec.rb b/spec/hashie/array_spec.rb
index 0c35b1e..ee14a82 100644
--- a/spec/hashie/array_spec.rb
+++ b/spec/hashie/array_spec.rb
@@ -1,28 +1,26 @@
 require 'spec_helper'
 
 describe Array do
-  with_minimum_ruby('2.3.0') do
-    describe '#dig' do
-      let(:array) { Hashie::Array.new(%i[a b c]) }
+  describe '#dig' do
+    let(:array) { Hashie::Array.new(%i[a b c]) }
 
-      it 'works with a string index' do
-        expect(array.dig('0')).to eq(:a)
-      end
+    it 'works with a string index' do
+      expect(array.dig('0')).to eq(:a)
+    end
 
-      it 'works with a numeric index' do
-        expect(array.dig(1)).to eq(:b)
-      end
+    it 'works with a numeric index' do
+      expect(array.dig(1)).to eq(:b)
+    end
 
-      context 'when array is empty' do
-        let(:array) { Hashie::Array.new([]) }
+    context 'when array is empty' do
+      let(:array) { Hashie::Array.new([]) }
 
-        it 'works with a first numeric and next string index' do
-          expect(array.dig(0, 'hello')).to eq(nil)
-        end
+      it 'works with a first numeric and next string index' do
+        expect(array.dig(0, 'hello')).to eq(nil)
+      end
 
-        it 'throws an error with first string and next numeric index' do
-          expect { array.dig('hello', 0) }.to raise_error(TypeError)
-        end
+      it 'throws an error with first string and next numeric index' do
+        expect { array.dig('hello', 0) }.to raise_error(TypeError)
       end
     end
   end