Need the ability to run without Mutation and without Breeding

[LydiaFrance]

In order to test 1v1 battles we need a way to run without mutation and without breeding.

[philswatton]

Without breeding has been added in #20. Without mutation hasn't been explicitly added but the mutation probability can be set very near 0 - could easily be added to turn it off completely?

Or could be quickly added?

[phinate]

i've added this in src/p2lab/genetic/genetic.pyin #35 by just special-casing 1v1s to skip the crossover/mutation for now :)