Add: More comments

Signed-off-by: Kevin Conway <kevinjacobconway@gmail.com>
Add: A converter function to the public API

This function converts any function into one that returns a
promise. It should be useful for working with non-async libraries.

The NPM version is bumped to 4.1 to represent the API addition.

Tests were also added with this feature.

Signed-off-by: Kevin Conway <kevinjacobconway@gmail.com>
Add: Function names for better debugging

Signed-off-by: Kevin Conway <kevinjacobconway@gmail.com>
Add: Docs for recent additions to API

Signed-off-by: Kevin Conway <kevinjacobconway@gmail.com>
Change: NPM package description to match docs

Signed-off-by: Kevin Conway <kevinjacobconway@gmail.com>
Merge pull request #8 from kevinconway/upkeep

Complete some package upkeep