Load local stl file from assets in react native

@ryantrem has a post on this subject: Error: Cannot load cubemap because 6 files were not defined - #58 by ryantrem

The base64 method is the quick and dirty solution. Will that work for you? If you have small files, it probably will. If not, the location to put the files will be platform-specific.

Let us know if you have trouble figuring it out.