Make compatible with `stack-trace` module

[vjpr]

Would be cool if it could be used with the stack-trace module to filter v8 CallSite objects.

Use case

I want to get the file name of the caller of an async function.

I am using Babel with ES7. My call stacks contain lots of generated function calls to regenerator, core-js, Promises/bluebird, etc. This makes it difficult to find the correct calling function in user code.

At the moment I would have to implement manual parsing of the stack string.

[cjohansen]

Feel free to shoot a PR, and I'll merge.