improve error handling - print error rather than crash
add getArgTypes command

Which allows you to see what arguments you need to pass to a function.
move Copay.js -> API.js, and handle case of no command better

* API is a more appropriate name for what this is. It is intended to be the
 interface used by external apps.
* The case where you run "copay" with no command is now handled better.
added type coercion for command-line

All inputs from the command are strings, but sometimes an argument needs to be
something other than a string. This adds basic type coercion, so you can input
objects and numbers as well.
check for present of callback in args correctly
add some basic tests for the structure of the API
add basic integration with wallet

...and further tests and stuff
convert from ? notation to more concise || notation
use decorator
Merge pull request #42 from ryanxcharles/feature/command-line-2

WIP: More command-line stuff