Fixes typo in SYNOPSIS.
Allow domain and version of the API url to be settable via
MetaCPAN::Client.

The docs say you can set these in the request object directly, but they
also say MetaCPAN::Client->request is for internal use.  It would be
easier if these attributes were settable when creating a new client,
just as the UA is.
Merge pull request #21 from CPAN-API/oalders/domain

oalders/domain