Revert "Add unit.get_race method for forward compatibility."

This reverts commit 88cf357.

Author: GraylinKim

sc2reader/data/__init__.py

@@ -272,9 +272,6 @@ def __init__(self, unit_id, flags):
         self.hallucinated = (flags & 2 == 2)
         self._cmp_val = (self.id << 16) | self.type
 
-    def get_race(self):
-        return self.race
-
     def __str__(self):
         return "{0} [{1:X}]".format(self.name, self.id)