Comment 0 for bug 1691517

A recent merge that added a mkfs.ext4 tests has a hard coded location for the binary of mkfs.ext4. The result is that on centos 7, which has the command in a different location than Ubuntu, is a failed test:

https://paste.ubuntu.com/24589593/

Steps to reproduce:
lxc launch images:centos/7 c7
lxc exec c7 bash
yum install --asumeyes python-pip
yum install --assumeyes git python-pip file e2fsprogs
pip install setuptools tox virtualenv contextlib2 httpretty mock nose pep8 unittest2
git clone https://git.launchpad.net/cloud-init
cd cloud-init
tox