[Prio 0] Account for different python string types during setup_code_coverage

[JacobCallahan]

During our latest RHEL 7 ISO installation attempt, the installer ran into this issue.

run: mkdir -p /etc/coverage
Traceback (most recent call last):
...
  File "/home/jenkins/workspace/provisioning-6.2-rhel7/automation_tools/__init__.py", line 737, in setup_code_coverage
    coveragerc_file.write('[run]\n')
TypeError: unicode argument expected, got 'str'

I did some quick searching and found a possible solution

try:
    # Python 2
    from cStringIO import StringIO
except ImportError:
    # Python 3
    from io import StringIO

Then remove io. from the rest of the code base.

[JacobCallahan]

Looking at our code, it looks like that solution above probably won't work, since we try to import from essentially the same module.

[kbidarkar]

Fixed in #655