Added support for account.retrieve

https://stripe.com/docs/api#retrieve_account
Handle HTTP error to avoid throwing exceptions
Added more error information when a stripe error occurs.
Added documentation for the error object.
Updated the errors test for the new error object.
Removed console log.
Merge pull request #38 from onmodulus/master

Added a few more properties to Errors returned from Stripe
Add charges.capture method

Data is optional. If given, it should be an object with the parameters amount and/or application_fee. 
Update README.rd, adding charges.capture
Adding tests for charges.capture

Two new tests: capture a charge fully, and only part of a charge.
Merge pull request #37 from slajax/master

Pass an object as an argument to customer.list and coupons.list
Merge pull request #32 from forty/master

Handle HTTP error to avoid throwing exceptions
Merge pull request #40 from Dashlane/master

Add support for charges.capture
Merge pull request #31 from m5m1th/master

Added account.retrieve