upick update to notebook

Add GPU acceleration (timsainb#14)

* added pad clipping flag

* added tensorflow backend

* updated docstrings

* updated readme

* updated readme

* updated package version

* updated readme

* updated readme

* updated website

* updated testing

* updated testing and black formatting

* update testing

* added test requirements

* updated travis yml to install requirements-txt

* updated travis yml

* updated test-req

update readme