Properly invalidate cache for get_*_by_name methods

Use the original name for invalidating the cache on the
get_project_by_name and get_domain_by_name when performing update
operations on the name attributes.

Change-Id: If58a3b0a47501096f9fa9eb9cd7a6057f7b29298
Closes-Bug: #1311142
fix flake8 issues

Fixes the following flake8 issues:

- import shadowed by loop variable (flake8 F402)
- list comprehension redefines 'role_ref' (flake8 F812)

Change-Id: Ida64ccc9d7ee8b2ecd110a908615d3a94e93785c
Updated from global requirements

Change-Id: I1628854fac8bf66f8bc28648d28fba253d9c04af
Merge "fix flake8 issues"
Merge "Updated from global requirements"
Merge "Properly invalidate cache for get_*_by_name methods"