Handling Canada Po. Shipments w/o tracking info

The exception thrown under the scenario where no tracking information
exists is quite different from the standard case. Rather than calling
`e.response.body` on an object that does not have a response, we now
utilize the `message` attached to the object.
Updating to build the correct objects
Updating test coverage for No Tracking from CA Po.
Formatting: Fixing weird spacing
Merge pull request #154 from akeem/improve_no_tracking_scenario_for_canada_post

Improving  the way we react to Canada Post shipments without tracking info