Added a new external module for running commands
Change RunException to have long/short string representations
Use External.run in Artifacts
rename {new,old}_omero to omero){cli,bin}
Use External.omero_{cli,bin} in Upgrade,UpgradeUnix

Todo: WindowsUpgrade
Add a unit test for UnixUpgrade
Use a specific Exception specification

Using plain Exception or nothing means pytest and Mox don't pick up errors.
Add __init__.py to test directories
Inadvertently rethrown an exception, removed

Also made exception catches more specific
Run unit and integation tests separately in Travis

If the integration test times out (server download takes too long) you can still check whether the unit tests passed.
Added DbParser for command line args

DB arguments may be common to both db and server admin commands
First attempt at some database administration commands
DbAdmin now takes init/upgrade as a command

Also fixed the sorting of SQL versions in the new server
Automatically attempt to upgrade DB in omego upgrade

New flag added, --upgradedb, defaults to false
Handle DEV schema versions
Replace psycopg2 module with psql binary
Move psql version output to start. Fix flake8 problems.
Add a very basic db connection check
Add mocked db unit tests
Fix db to work with the new external module