Enable: H904 Wrap long lines in parentheses instead of a backslash

[Aaron Rosen]

H904 Wrap long lines in parentheses instead of a backslash

See: https://review.openstack.org/#/c/135881/5 for example

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/143032

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/143032
Committed: https://git.openstack.org/cgit/stackforge/congress/commit/?id=c02255fcdbe03e6aedb72007e254a9355796e072
Submitter: Jenkins
Branch: master

commit c02255fcdbe03e6aedb72007e254a9355796e072
Author: Madhu Mohan N S <email address hidden>
Date: Fri Dec 19 16:07:21 2014 +0530

    Enable H904: wrapping using parantheses

    Enabled H904 on tox and changes made in relevant files to adhere to H904
    guideline. Backlash based line wrapping modified to use bracket based or quote
    based wrapping mechanism with modified indentations.

    Change-Id: I10b1ce7fbc230ff3167adbb06e0982b4cc0b0bb7
    Closes-Bug: #1398555