Enable pep8 tests for the Nova Ironic Driver

Enable pep8 tests for the Nova Ironic Driver and fix the current pep8
errors. Being able to run pep8 tests against the driver helps the
development because it captures problems like syntax errors, unbound
variables, duplicated methods, etc...

Change-Id: If1da455bb8669b56267cb3ecf45369d5d83a86b7
Merge "Enable pep8 tests for the Nova Ironic Driver"