App Type is ignored when running rake tasks on a rails app.

[zee-roostify]

Consider the following scenario:

Given a brand spanking new Rails app with bugsnag configured with `app_type="service-a"`
When I run `bin/rake bugsnag:test_exception`
Then I receive an exception with an app_type of `rake`
Instead I would like to receive an exception with the app_type of `service-a`

When looking at the rack middleware, I noticed that it used an ||= to set the app_type; which seems reasonable. However on rake, it always sets the app_type to rake

Because we have a service oriented architecture, we were planning to use the app_type to distinguish between the many different services in our deployments, (mailer-api, mailer-worker, mailer-rake) so that all exceptions stream in to the same project and can be filtered/explored/acted upon in this manner.

[zee-roostify]

Whoops. Hit enter and it submitted before I filled out. One moment!

[kattrali]

Thanks for the detailed report, @zee-roostify. This makes a lot of sense! Scheduling this in as an enhancement.