Schulze is implemented incorrectly

[bradbeattie]

http://en.wikipedia.org/wiki/Schulze_method

• 16:B>A>E>D>C
• 27:C>B>A>E>D
• 17:C>E>A>D>B
• 31:D>A>B>C>E
• 9:E>D>B>C>A

Should result in a win for A, whereas the current system ties it between A, B and C.

[bradbeattie]

This can be confirmed in the unit test test_disagree_with_ranked_pairs.