Hooked up markets to database and changed card UI

Also added a script to update markets. To run it, use python manage.py
shell < ./scripts/updateMarkets
Merge branch 'master' into market-hookup
Fixed generation/styling of hours string.
Added UI for joining/leaving markets.

This change includes all client and server side changes to join/leave
markets. Currently, they are displaying on the client side on the
seller’s page, but not on the vendor details page.

We are making a few extraneous database calls to ensure that all client
side information is kept up to date with the server. If these prove to
be too expensive at launch, we can cut back.
Added markets to vendor details page.
Merge branch 'master' into market-hookup

Conflicts:
	src/client/app/scripts/directives/marketcard.js
	src/client/app/scripts/services/stateservice.js
	src/server/be_local_server/serializers.py
	src/server/be_local_server/views.py
Fixed market joining workflow

Updated message that is displayed when a user has joined all available
markets. Also made the markets tab enabled by default.
Changed tab color
Merge branch 'master' into market-hookup
Finalized market card UI

Images are still not in the database, but this should wrap up the UI
changes on the front end.
UI changes to markets cards
Added images for markets
Hooked up images to market cards.
Merge pull request #40 from rpanjwani/market-hookup

Market hookup