Feature: Support for source-maps to decode release stack traces

[IjzerenHein]

Currently, the stack traces in release are very hard to read. The line-numbers refer to absolute line-numbers (and column-numbers) in the bundle.js.
Using source-maps these can be decoded to show the correct source file-name and line-number.

[sibelius]

@IjzerenHein have u found a solution?

[sibelius]

@ianlin this support getting js errors?

maybe this could help https://github.com/bugsnag/bugsnag-react-native/blob/master/lib/Bugsnag.js#L37

[ianlin]

Hey guys sorry for this, was extremely busy on work, if anyone wants to submit a PR I will be appreciated :D