Update credits and news
Force float in stochastic graph.
Test stochstic graph with ints
Doc, whitespace, formatting, style cleanup.
Merge pull request #830 from hagberg/stochastic-float

stochastic_graph() bug, need to force float
Merge pull request #907 from hagberg/link-fixes

Link fixes
Merge remote-tracking branch 'upstream/master' into credits-news-release

Conflicts:
	doc/source/reference/credits.rst
	doc/source/reference/news.rst