multi-module project support

[Aidan Follestad]

Something like this:

gpm app:install okhttp
gpm common:utilities:install okhttp

It could probably simple search for a build.gradle in the given path

[theapache64]

@afollestad Alright. that'd be very useful

[theapache64]

@afollestad

Done!

The syntax would be

gpm :module install <depName>
gpm :moduleDir:module <depName>

eg:

gpm :features:auth install okhttp

This feature will be available from 1.0.4-alpha01 :)