Update ReadMe.rst and History.rst

Version 0.8.0

version 0.7.1

Add to travis, python 3.7 (requires xenial dist) and pypy3.5-6.0; pyc…

…oin == 0.80 (now pegged)

Version 0.7.0

Version 0.6.1

Update ReadMe for xprv and xpub key examples

ReadMe Rendering issues on PyPi

Version 0.5.5 - Updated ReadMe. Changed default fee to 1 sat/byte.

version 0.5.4