Stop overriding respond_to?

- This was causing an issue, where for some reason, a call to :respond_to? by RSpec (expect().to) could not find the method ‘respond_to?’ on the object.   Having this override here, caused a call to the borwser#respond_to?(:respond_to?) which came back as true; and caused failures down the road.
Version bump to 0.5.2