OpenBazaar/OpenBazaar — pull request #842 by Renelvon (2014-10-23 01:12:55+00:00)
Title: [WIP] Migrate to bitcoin from pybitcointools. Fix #552.

### Motivation
The familiar `pybitcointools` package is currently developed under the name `bitcoin`.

### Changelog
* Change the dependency name from `pybitcointools` to `bitcoin`.
* Upgrade to version `1.1.19`, which includes some bugfixes.