Fix undefined glance_host in get_glance_client
Fix undefined glance_host in get_glance_client

get_glance_client is stubbed in the tests, so they didn't catch it.
Added tests to catch it.

Also, add myself to Authors file.

Change-Id: Ie7c1e90c3999f7f4b45af1cedd7c3570b48af43e

n0ano/ganttclient