Fix the help messages to specify image/flavor name

User can specify flavor/image name as the arguments of "nova boot"
command instead of their ids, but the help messages does not explain
that. This fixes the help messages.

Fixes: bug #1211156

Change-Id: I47813c8ebbe5fc83d627f016e3751918b3ab11cb
Fix and gate on H501, no locals for string formatting

Change-Id: I07e4a1a733639a343d4b3ee20927d50ba04bd7a3
Upgrade to Hacking 0.7

There was a bug in hacking 0.6 that broke H202, assertRaises Exception
too broad, so switch to Hacking 0.7 and fix the one H202 bug.

Change-Id: I0ec9532ffbb6b3c8dbd775e6da7bc879b0a6737a
python3: Fix imports for py2/py3

Python3 reorganized the standard library and moved several functions
to different modules. Six provides a consistent interface
to them through the fake six.moves module.

However, the urlparse, urllib2, etc modules have been combined
into one module which Six does not support so we do it via
py3kcompat.

Modules such as StringIO and CStringIO have been removed
completely so we use the io module.

Change-Id: I53adac11b634de2c710fc39def36bcec96366710
Signed-off-by: Chuck Short <chuck.short@canonical.com>
Merge "Upgrade to Hacking 0.7"
Merge "Fix and gate on H501, no locals for string formatting"
Merge "python3: Fix imports for py2/py3"
Merge "Fix the help messages to specify image/flavor name"