v1.2.0

Release highlights

Improved custom stack trace options, including pkg/errors StackTrace
Improved error unwrapping, including new pkg/errors Unwrap
Enhanced diagnostic info sent with Rollbar payloads
Improved panic handling

Pull requests

Add support for pkg/errors stack trace extraction, #53
Allow custom error unwrapping (and support Unwrap automatically), #64
Diagnostic info, #65
Wrap functions with arguments, and add Rollbar to defer/recover functions, #66