add doi grabber function from neurovault. update requirements.txt for functions needed by said function
add doi grabber function from neurovault. update requirements.txt for functions needed by said function

poldracklab/cogat,poldracklab/cogat,poldracklab/cogat,rwblair/cogat,rwblair/cogat,rwblair/cogat,poldracklab/cogat,rwblair/cogat