Refs #5029: Allow initial organization and location to be specified during seed.

Initial seed data can now be specified by running:

rake db:seed SEED_INITIAL_ORGANIZATION=MyOrg SEED_INITIAL_LOCATION=MyLoc

This also has the side effect of allowing creation of multiple org/location
by running seed with different values for each.
Merge pull request #4336 from ehelms/refs-5029

Refs #5029: Allow initial organizationd and location to be specified dur...