lotterysim: remove redudant file path constant

script/research/lotterysim/core/constants.py

@@ -33,4 +33,3 @@ F_MAX_HP = Num(F_MAX)
 EPSILON_HP = Num(EPSILON)
 REWARD_MIN_HP = Num(REWARD_MIN)
 REWARD_MAX_HP = Num(REWARD_MAX)
-VESTING_FILE='example.csv'