Run glance-manage as {{ system_user }}

Currently this task is run as root, however as glance has no separate
glance-manage.log file, this _could_ result in
/var/log/glance/glance-api.log being owned by root.  This change causes
glance-manage to be run as {{ system_user }} which should eliminate
this from happening.
Updates glance client version to fix juno

This update changes the glance client sha to a version that will
allow for the internal URL to be used which was broken in version
0.14.1/2.
Ensure OpenStack commands are run as correct user

Currently, a number of OpenStack commands are run as root (namely,
those management related commands to handle db creation/migrations).
This change updates these affected tasks to use sudo to run the commands
as the correct user.

We also make a few other minor changes, namely:

- updating some hard-coded users to reflect {{ system_user }} instead
- removing nova_compute_sshkey_create role from nova-compute.yml
  playbook (this role is already listed in nova-compute-keys.yml, which
  is included in nova-all.yml)
- adding a vars_files to nova-compute-keys.yml so we can reference
  {{ system_user }} instead of the hard-coded nova user
- updating the 'Create the nova SSH key if it doesnt exist' task to use
  sudo rather than su
Create alarms for discovered devices

Currently, we create checks for {sda,sdb,sdc}, but not every server will
have these devices.  This commit loops over {{ ansible_devices }}
instead so we create an alarm for any discovered device.

Additionally, if a user variable called maas_excluded_devices exists,
we'll skip over those devices when creating alarms.
Tool to test RPC MaaS configuration

This tool originally lived in rpc-maas repo but is being moved since
it's not actually a plugin.  To document, the tool does:

- prints out triggered alarms
- tests all checks for an entity and alerts if a check fails
- deletes all checks (and alarms)
Merge pull request #518 from mattt416/issue_430

Create alarms for discovered devices
Merge pull request #503 from mattt416/issue_497

Run glance-manage as {{ system_user }}
Merge pull request #507 from mattt416/issue_504

Ensure OpenStack commands are run as correct user
Merge pull request #524 from mattt416/add_maas_tool

Tool to test RPC MaaS configuration
Merge pull request #508 from cloudnull/glanceclient-patch

[JUNO] Updates python-glanceclient release