Add support for providing a list of field names to try instead of just using "main"

[christoffer-dropbox]

This adds support to provide a list of field names in package.json to try when resolving modules. This is useful when using tsconfig-path in other environments than Node, such as Webpack (see tsconfig-paths-webpack-plugin for an example).

This is a required change to tsconfig-paths in an attempt to solve the issue described in: dividab/tsconfig-paths-webpack-plugin#20.

This PR shouldn't affect current usage, as the API still defaults to using "main", as verified by existing test cases.

[coveralls]

Coverage decreased (-4.7%) to 81.754% when pulling 5745558 on christoffer:master into ee472ad on dividab:master.

[jonaskello]

Nice work! I'll have to merge this one before I can get to the plugin. Would you care to add the API additions to the readme too? Specifically the new mainFields param that is now part of the createMatchPath and matchFromAbsolutePaths.

[christoffer]

Ah, thanks for pointing out I forgot those! Fixed.

[jonaskello]

Thanks!

[jonaskello]

Published in 3.4.0.