Make RSpec::ExampleWording case insensitive.

Closes rubocop#31 - thanks to @EsterYtterbrinkAtTrialbee

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Change log
 
+# master
+
+* Make `RSpec::ExampleWording` case insensitive. ([@geniou][])
+
 ## 1.2.1
 
 * Add `RSpec::VerifiedDoubles` cop. ([@andyw8][])

lib/rubocop/cop/rspec/example_wording.rb

@@ -28,7 +28,7 @@ def on_block(node) # rubocop:disable Metrics/AbcSize
 
           arguments = *(args.first)
           message = arguments.first.to_s
-          return unless message.start_with?('should')
+          return unless message.downcase.start_with?('should')
 
           arg1 = args.first.loc.expression
           message = Parser::Source::Range

spec/rubocop/cop/rspec/example_wording_spec.rb

@@ -18,6 +18,15 @@
     expect(cop.highlights).to eq(['should do something'])
   end
 
+  it 'finds description with `Should` at the beginning' do
+    inspect_source(cop, ["it 'Should do something' do", 'end'])
+    expect(cop.offenses.size).to eq(1)
+    expect(cop.offenses.map(&:line).sort).to eq([1])
+    expect(cop.messages)
+      .to eq(['Do not use should when describing your tests.'])
+    expect(cop.highlights).to eq(['Should do something'])
+  end
+
   it 'finds description with `shouldn\'t` at the beginning' do
     inspect_source(cop, ['it "shouldn\'t do something" do', 'end'])
     expect(cop.offenses.size).to eq(1)