Typing definition for td.object doesn't support constructors with arguments

[caseyhoward]

For example, the following doesn't work:

class Blah {
  constructor(private x: number) {}
}

let blahDouble = testdouble.object(Blah);

It generates the following error:

[ts] Argument of type 'typeof Blah' is not assignable to parameter of type 'new () => Blah'.

[caseyhoward]

Fixed by #185