Update credits and news
Force float in stochastic graph.
Test stochstic graph with ints
Doc, whitespace, formatting, style cleanup.
Don't copy subgraphs in cuthill_mckee_ordering().

The connected_component_subgraphs() function used in the cuthill_mckee_ordering() makes a copy.  That causes new node objects to be created which might not be desirable when returning a node ordering if the hash changes when a new object is created. Fix by not copying nodes when forming a subgraph of connected nodes.
Adjacency list format write adds extra delimiter

Remove trailing delimiter from write_adjlist().  Fixes bug of adding an extra anonymous node when reading back file written with write_adjlist()
Add delimiter test for multiline_adjlist format
Whitespace cleanup
Whitespace cleanup
Don't modify input list in _all() operators.
Merge pull request #900 from hagberg/union-all-pop

Don't modify input list in _all() operators.
Merge pull request #899 from hagberg/adjlist-delimiter

Extra delimiter from write_adjlist()
Merge pull request #856 from hagberg/rcm-copy

Don't copy subgraphs in cuthill_mckee_ordering().
Add system site packages to travis.ci
Add numpy and scipy packages with apt-get to travs.ci
Fix .travis.yml error
Add more optional packages to travis builds
Fix typo and add more travis.ci packages
Add pygraphviz and pydot to travis.ci config
Add remaining packages for travis.ci