Enhance in project

This PR should massively improve your Bugsnag dashboard by doing the following:
- Set any stacktrace lines which do *not* contain `node_modules` as `inProject`
- Strips common path information from the start of stacktrace lines

Things to consider:
- You might want to change the inProject regex to instead be a whitelist of paths that you care about, I've simply marked all node_modules as not in project.
- The regex for stripping common path information probably won't work on windows, so you'll need to update that before you release the windows version