The builtin basestring abstract type was removed in python3,
use str instead, we need to use six.string_types to replace
the basestring for py3 compatibility.
This patch was generated by the following tool using 'basestring'
option.
https://github.com/haypo/sixer
Command:
python sixer.py -w basestring murano/
This also adds a check to murano/hacking/checks.py that should
catch this error in the future.
Blueprint murano-python-3-support
Change-Id: I26c236ce6dd2fffd6a4ca50e55ad62deb01bd9dd
f963039bd7