The reference for a request verb is now the string which is used
everywhere else, instead of the symbol corresponding to it. This was an
artifact from the import from httprb, and there is no advantage in it,
since these strings are frozen in most use cases, and the
transformations from symbol to strings being performed everywhere are
prooof that keeping the atom isn't really bringing any benefit.
* Webmock allows users to stub a request using a URI with query
parameters, as a shortcut instead of using `with...`
* The Webmock adapter did not construct a URI that included the
`request.query`, causing stubs that had the same host/path, but
different queries, to return incorrect results
