Add DFS over edges.
Add some additional comments.
Add import statement for doctest.
Fix doctest again.
Add enum34 as a dependency.
Make edge_dfs use a new Direction enum.
Add option for 'reverse' traversals.
Violating 80 character rule to make doctests happy.
Use 'forward' and 'reverse' strings to indicate traversal direction.
Remove enum import statement.
Use import * in traversal submodule.
Docstring changes for edge_dfs and company.
Fix bug for reverse edge DFS.
Add comment on unit tests and hash randomization for partially ordered
output.
Docstring.
Add entry for `edge_dfs` in 2.0 release notes.
Improve memory footprint of edge_dfs.
Merge pull request #1193 from chebee7i/edgedfs

Add DFS over edges.