Bug 1236894 - Add missing trailing slash to python client API URLs
Bug 1236894 - Add missing trailing slash to python client API URLs

To avoid 301 redirects during the request. This only affects client
functions that are not project-specific (the others use
`_get_project_uri()` instead).

KWierso/treeherder,kapy2010/treeherder,tojonmz/treeherder,akhileshpillai/treeherder,KWierso/treeherder,wlach/treeherder,tojon/treeherder,tojonmz/treeherder,tojonmz/treeherder,akhileshpillai/treeherder,kapy2010/treeherder,edmorley/treeherder,edmorley/treeherder,glenn124f/treeherder,wlach/treeherder,akhileshpillai/treeherder,wlach/treeherder,akhileshpillai/treeherder,tojon/treeherder,edmorley/treeherder,tojon/treeherder,wlach/treeherder,tojonmz/treeherder,glenn124f/treeherder,akhileshpillai/treeherder,wlach/treeherder,glenn124f/treeherder,glenn124f/treeherder,kapy2010/treeherder,KWierso/treeherder,glenn124f/treeherder,edmorley/treeherder,wlach/treeherder,tojonmz/treeherder,kapy2010/treeherder,tojon/treeherder,akhileshpillai/treeherder,glenn124f/treeherder,kapy2010/treeherder,tojonmz/treeherder,KWierso/treeherder