Simple test case for rebelidealist/stripe-ruby-mock#20
Setting up files
Updating test case
Keeping it DRY
Formatting
Updating card exp_month, and exp_year to always return integers.
Merge remote-tracking branch 'upstream/master' into bug/20-customer-create

* upstream/master:
  Changing the status image url
  Adding rake to gemfile
  Travis CI
Merge pull request #21 from GeorgeErickson/bug/20-customer-create

Card API: Create