CLC-3158: Fixed "FinAid Messages: investigate date discrepancy"

https://jira.media.berkeley.edu/jira/browse/CLC-3158

Dates given by the feed that happen at midnight (ie: 2013-03-03),
should always be in Pacific (server) time, not GMT.
DateTime was being used instead of Date for parsing and we needed
to use to_time_in_current_zone to build server-zoned dates.

Wrote spec to make sure my_fin_aid returns the correct epoch and is not using GMT