Add a lipsum generator for Conpherence Rooms

Summary: Builds a basic room generator for Conpherence, picks a random name, adds 10 random users to it, sets view and edit policy to all users.

Test Plan:
bin/lipsum generate conpherence

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: Korvin

Differential Revision: https://secure.phabricator.com/D17699