cleanup ~/.maascli.db on failure

First we move up the step of setting proper ownership of ~/.maascli.db.
We also make sure to cleanup that file if failure to login occurs as
the database gets created regardless.

Fixes #199

Signed-off-by: Adam Stokes <adam.stokes@ubuntu.com>
update uninstall instructions for landscape

We don't want to automatically purge everything because of
landscapes requirements. This updates the uninstall instructions
printed to the user during a `openstack-install -u` if a landscape
installation is detected.

Fixes #200

Signed-off-by: Adam Stokes <adam.stokes@ubuntu.com>
Disable adding ceph units until can be fully tested

Signed-off-by: Adam Stokes <adam.stokes@ubuntu.com>
Merge pull request #238 from Ubuntu-Solutions-Engineering/patch-199-fix-maasclidb-perms

cleanup ~/.maascli.db on failure [r=sparkiegeek]
juju api expects a string not boolean

In the swift charm we previously were setting a Boolean as
an option for defining our 'use_swift' config item. Either
the api changed what it accepts or something else is going
on as this has worked in juju versions 1.18.x.

Fixes #210

Signed-off-by: Adam Stokes <adam.stokes@ubuntu.com>