Cannot set revision_limit when creating a site

[elsherif]

when creating a new site (sites.create(site_item)) the revision_limit setting doesn't get set. It will be set to default 25 and the parameter 'revision_limit' will be ignored. I have checked the request_factory.py and it seems that this parameter is not set when creating a new site!

[bcantoni]

@elsherif cleaning up old issues, it looks like this was fixed in #847.