Addresses two sources of inconsistency in the output of enumpoly:

[tturocy]

1. In the polynomial system solver, checks whether perturbations attempting to move off of a singular point are successful, rather than failing silently.
2. Make the iterator over sequences iterate sequences in a deterministic order.

[tturocy]

@rahulsavani We can put this on our agenda for the next meeting, specifically w/r/t whether we want to do anything else with the tests for this method.

[rahulsavani]

This looks good, but I think we should expand the tests a bit. I will do that, but welcome some input:

• I will make the 4x4 coordination game not stop after only 1, but at least a few more
• I will add Bernhard's 75 eq 6x6 game, as an efg and again set a >1 but not too large stop after (by the way, finding all seems super slow); I will also take this opportunity to put that game in the catalog in a separate PR
• I will add some "true" EFGs with multiple equilibria, which will perhaps be the most important addition, maybe one with 2 players and one with 3 players

@tturocy
For the last bullet, I can come up with some examples myself, but wonder if you know any such games from papers or textbooks that would be suitable and that I could put into the catalog at the same time (I will take a pass on the existing catalog too in case I forgot about any suitable ones)?