O295and o296 sponsorship start date validation

https://osraav.atlassian.net/browse/OSRA-295
https://osraav.atlassian.net/browse/OSRA-296

Model validation for Sponsorship.start_date 
- date can't be blank
- date can't be an arbitrary string
- date can't be later than the first of next month

plus rspec  and cucumber tests

Needs ruby 2.1.5
Me and Andrey paired on all this.
There is a bigger problem I noticed:

because we have   travel_to   and other variables in a describe block but not in a before it will be run at the start of the test (right after we run rspec).  It is traveling to 15-12-2014 before any test starts (any file) and never goes back.

I think the solution is to put the travel_to and other variables in a before(:all) and use instance variables (@today, @yesterday ...) . This way we can have access to them in the    it block    too.
I am confused :)