fix rspec

Author: Romex91

spec/react_on_rails/prender_error_spec.rb

@@ -65,7 +65,9 @@ module ReactOnRails
  it "shows truncated backtrace with notice" do
  message = expected_error.message
  expect(message).to include(err.inspect)
- expect(message).to include(err.backtrace.first(15).join("\n"))
+ expect(message).to include(
+ "spec/react_on_rails/prender_error_spec.rb:20:in `block (2 levels) in <module:ReactOnRails>'"
+ )
  expect(message).to include("The rest of the backtrace is hidden")
  end
  end