Add a test to confirm that .rubocop.yml is used

Author: danielmorrison

spec/cc/engine/rubocop_spec.rb

@@ -42,6 +42,26 @@ def method
         assert !includes_check?(output, "Lint/UselessAssignment")
       end
 
+      it "respects the default .rubocop.yml file" do
+        create_source_file("foo.rb", <<-EORUBY)
+          def method
+            unused = "x" and "y"
+
+            return false
+          end
+        EORUBY
+
+        create_source_file(
+          ".rubocop.yml",
+          "Lint/UselessAssignment:\n  Enabled: false\n"
+        )
+
+        output = run_engine
+
+        assert includes_check?(output, "Style/AndOr")
+        assert !includes_check?(output, "Lint/UselessAssignment")
+      end
+
       it "reads a file with a #!.*ruby declaration at the top" do
         create_source_file("my_script", <<-EORUBY)
           #!/usr/bin/env ruby