merge multi install paths into one

This takes the same approach as the Landscape whereas if
a MAAS server ip and apikey are provided it will do the
MultiInstallWithExistingMaas, otherwise it assumes a new
MAAS install will be performed and continue down that
path.

Signed-off-by: Adam Stokes <adam.stokes@ubuntu.com>
Merge pull request #191 from Ubuntu-Solutions-Engineering/patch-merge-multi-into-one-path

merge multi install paths into one
add ability to point at fake maas node json to test UI
add fake maas machine data
rename env var
fix pyflake error

Signed-off-by: Adam Stokes <adam.stokes@ubuntu.com>
re-add workaround comment
use total # of satisfying machines in filter label, not total # machines
fix typo