fixed computing of shortest path's weight for Floyd-Warshall algorithm for edges having weight != 1.0
The class MinSourceSinkCut.java contained a bug which occasionally resulted in an incorrect solution. This error is not traced by the unit tests class.
Merge pull request #18 from plprofetes/master

fix for Floyd-Warshall algorithm for non-default weighted edges
Credit for plprofetes bugfix.
Replaced assertTrue with assertEquals with epsilon.
Merge pull request #20 from jkinable/master

Bug fix for MinSourceSinkCut.java