Fix illegal dates test.

There was a bug that had the illegal dates getting set up wrong, so
that start would be earlier than deadline and so it was possible to
find these dates as illegal via the wrong mechanism and still have an
error in them.  Fixed with this commit.
Use Timecop for making time work "properly"

By freezing time, we will be sure that the times we set for tests
doesn't advance before the tests against those same times execute.
Timecop simply makes sure that the time looks like it is fixed at some
point in time.  Now all references to now will return the same value
since time won't be advancing and things will "just work."

Possible Conflicts:
	Gemfile
	Gemfile.lock
Merge branch 'master' of https://github.com/geisler/game_contest_server

Conflicts:
	Gemfile.lock