temp commit. trouble in paradise, see below.

I am attempting to strongly connect the EventItem to the
db, ie. dictating update behavior inside EventItem fields,
and I don't want spiders devs to have to deal with the biz
logic of formatting data. It is proving difficult to define
and verify schemas before they are submitted to the schemaless
data store.

On a side note, this is my first interaction with schemaless
dbs and I just now realized how much I appreciate having typed schemas
because you don't have to worry -as much- about verifying db updates.

Anyway, I'm going back on forth on how much biz logic I want to pack
into EventItem. This commit breaks the scraper but I wanted to make a
record of some code before I nuke it.

I'm thinking the EventItem -> db.update needs to be moved *back* to
pipelines.py haha. Design decisions. It's not very important at this
juncture anyway, so I'm going to move fwd as soon as it's working
properly. A good design should reveal itself as more spiders are
written and requirements known.