Coerce path parameter to allow URI objects to be passed as arguments

HTTParty.get(URI('http://google.com')) will throws the error URI::InvalidURIError: bad URI(is not URI?): http://google.com
Coercing the path to a URI and then to a string allows URIs to be passed as arguments and ensures nil will still throw 
Idea originated whilst reading Avdi Grimms' 'Confident Ruby'