Instantiating engines by passing the Engine constructor into resourceful.use()

[richmarr]

It looks like resourceful.engines contains a map of engine constructors, so resourceful.use() should really take a constructor rather than an object.

So you can do this:

var Engine = require('my-engine').Engine;
resourceful.use( Engine, {
    my:'config',
    goes:'in here'
});

Otherwise you'd have to instantiate the Engine then pass it in, which wouldn't fit the method any more.

Assuming this is a just a bug, so changed the validation from 'object' to 'function' and added tests to that effect. I may be missing something though.

[indexzero]

@richmarr Yes this is just a bug. I'll cherry-pick in the relevant commits.

[indexzero]

Cherry-picked. Thanks!