Added the development endpoint to the avalara.yml.example
Updated development dependencies to vcr >= 2.0, factory girl >= 4.0 and rspec >= 2.0
Updated cassettes for vcr v2.0
Updated factories for FactoryGirl 4.0
Changed the headers for the api to have a default value and include the accept and content type.
Renamed authentication to authorization because that is what it is.
Fixed api endpoint to match the host instead of the full url. Combined api username and api password to api basic auth and encoded it so special characters will match.
Updated failure fixture to include the newer headers.
Updated get tax success fixture to include the newer headers.
Added error message fields for tax response.
Changed get_tax to return response invoice instead of raising an error so it could have a useful response. Added missing tests for geographical_tax.