Types not resolving to `.js.flow` files #27

I'm using an npm package that transpiles its files then uses flow-copy-source to copy its flow annotated files to the package's lib folder. The result is there's an index.js file and an index.js.flow file. index.js.flow contains custom types exported by the application, while index.js has these stripped.

At compile time, the flow-bin binary resolves to index.js.flow instead of index.js, allowing the flow compiler to pick out the custom types. However, the flow-runtime babel plugin doesn't resolve index.js.flowfirst, causing flow-runtime to throw the error Error: Could not reference the given type.

If you could point me in the right direction in the code base I might be able to help submit a PR. If you have another suggestion on how I could fix this though I'd appreciate it!