Add a possibility to customize fixtures source
Add a possibility to customize fixtures source

This patch adds a possibility to provide custom git repo, gerrit
repo, branch and gerrit refs for fuel-noop-fixtures. Does not
affect deployment, only noop rspec tests.

Fuel-CI: disable

Docs update: I10a4572b98d715ce1382fc7533847e1c1f16f81b
Closes-bug: #1566220

Change-Id: I492716d21f9c81325a9f75aaf3b7a0894a5e00cf

stackforge/fuel-library,stackforge/fuel-library,stackforge/fuel-library,stackforge/fuel-library