ES6 Modules + flexible data loading

This is an exciting release because indian-ocean is now broken into es6 modules and brand new documentation. Adds a new convertData function which allows for converting from format to format. Aliases makeDirs to makeDirectories for less typing if you don't feel like typing. There's also an experimental browser bundle and some minor new features.

This is a breaking change because it drops support below Node 3 and changes the API for io.discernParser

See the CHANGELOG.md for a full list of changes.