MAINT: Updates copyright year of perf_tracking tests.
MAINT: Removes unused mock data function from gens.utils

This function is unused, and on the general path of moving testing
functions out of gens.utils
 # Please enter the commit message for your changes. Lines starting
MAINT: Removes alternate function from gens.utils

This function is no longer refrenced elsewhere in the codebase.
MAINT: Updates copyright year on gens.utils module.
MAINT: Moves create_trade out of gens.utils

Slight refactoring of moving create_trade so that it's alongside
other testing/mock data utilities, instead of part of the gens module.
MAINT: Uses Transaction object in tests instead of ndict.

So that Transaction object behavior is exercised, uses the Transaction
object in performance module tests instead of ndict.

Also, adds fields to the __init__ of Transaction, to make the
definition of the object more well defined.