pin requests lib to 1.2.0
pin requests lib to 1.2.0

fixes bug DHC-1286

There is an unstream bug in 1.2.1+ that causes IPv6 URLs not be
reassembled correctly.  The change was recent, so pinning to a recent
older version that does not contain the bug.

stackforge/akanda-appliance,stackforge/akanda-appliance,openstack/akanda-appliance,openstack/akanda-appliance,dreamhost/akanda-appliance,dreamhost/akanda-appliance