Bump version to 0.8.2

Version 0.7

Version 0.6.57

Paypal Authentication migration to gem #165

Issue/172 update test order mode (#173)

Feature- revert json api client upgrade changes #170

Feature/revert json api changes

Issue/167 test mode always set to true (#168)

Bug fix - Update `test_mode` method to return correctly if the order is a test order.

Issue/163 update cart create method (#164)

Update version.rb (#162)

Improve error messages thrown when json parsing fails (#154)

* Improve error messages thrown when json parsing fails

* Use raven_context instead of the error message

* Add Sentry context to internal server errors