fix: add assertion to example block

Author: nzlaura

lib/rubocop/cop/rspec_rails/minitest_assertions.rb

@@ -18,6 +18,7 @@ module RSpecRails
       #   refute_empty(b)
       #   assert_true(a)
       #   assert_false(a)
+      #   assert_response :ok
       #
       #   # good
       #   expect(b).to eq(a)
@@ -28,6 +29,7 @@ module RSpecRails
       #   expect(a).not_to be_empty
       #   expect(a).to be(true)
       #   expect(a).to be(false)
+      #   expect(response).to have_http_status(:ok)
       #
       class MinitestAssertions < ::RuboCop::Cop::Base
         extend AutoCorrector