Merge pull request #123 from aestrivex/updates

Merge updates into master

Merge pull request #121 from victoris93/master

Parallelize NBS

update version numbers

Merge pull request #65 from CarloNicolini/master

fixed community_louvain handling of negative_asym and negative weights

fix print statement in test case

update changelog

update changelog and README for 0.3.3 release