Excon.stub with :url should parse query to hash

[danp]

Related to #381 I noticed if a query is parsed out of a :url attribute passed to Excon.stub it's not being converted to a hash as one might expect.

[geemus]

Point taken. I wouldn't expect it to be converted for real requests (it seems inefficient to turn it to a hash and back to a string, if nothing else). But stubs might not match/work without this for mock stuff. Are you up for taking a stab at this or should I take it? Thanks!

[stale]

This issue has been automatically marked stale due to inactivity. It will be closed if no further activity occurs. Thank you for your contributions.