A fresh start...
Add tests for time util
Add lodash and a dev version of graphlib
Initial work on longest-path algorithm
Add feasible tree implementation + initial rank sketch
Add normalize function for rank
Initial implementation for assignLowLim
Initial work on cut value calculation
Minor doc tweaks
Initial work on leaveEdge
Include lodash in package for now
Initial implementation of enterEdge
Initial implementation of exchange for rank
Remove edgeIter
Collapse network simplex functions into a single module
Improvements to longest-path-test

- Simplify object construction.
- Add another test.
Initial work on net simplex
Add feasible tree to network simplex
More tests for network simplex
Assign low-lim and cut values to nodes during net simplex