Updated Autoloader to work with Test suite.
Updated Autoloader to work with Test suite.

Stash is located in '/src', while the test suite is in '/tests'. The
provided autoloader only supported '/src' which made testing without
composer difficult.

graphis/Stash,jaredtking/Stash,theUniC/Stash,andrerom/Stash,bankiru/Stash,andrerom/Stash,tedious/Stash,theUniC/Stash,localheinz/Stash,AndrewCarterUK/Stash,tedious/Stash,graphis/Stash,AndrewCarterUK/Stash,jaredtking/Stash,csburton/Stash,bankiru/Stash,localheinz/Stash,alawnchen/Stash,csburton/Stash,alawnchen/Stash