Prepare for functional testing by creating two new directories:
* ironic/tests/unit
* ironic/tests/functional
Move all files currently in ironic/tests/* to ironic/tests/unit/
Update imports from 'ironic.tests.YYY' to 'ironic.tests.unit.YYY'
Fix any PEP8 issues due to longer lines
Partial-Bug: #1491670
Change-Id: I1166f20adf8c84b2042b62e348926502a4851e08