Origination.
added requirements.txt.
added a trivial flask app.
assume our dir is alongside the swcarpentry dir.
updated ORM to work w/ latest model changes.
get rid of airport.people_facts.
added db.get_session(), flask config object.
app automatically builds roster.db on startup if needed. added readme.
added a docstring for create_roster_db().
added bootstrap and jquery.
embellished home page w/ bootstrap.
made index.html extend layout.html.
add very basic searching of instructors who teach python and/or r.
WTF, somehow I was using bootstrap 2 instead of 3.
upgrade to bootstrap3, use 2-column layout.
removed unused import.
added cities.py.
Merge branch 'master' of github.com:toolness/swcarpentry-awsmgrep

Conflicts:
	app.py
added a /cities.json endpoint.
order city search results by population.