fixes in relative imports

examples/pybullet/gym/pybullet_envs/minitaur/envs/minitaur_derpy.py

@@ -6,8 +6,13 @@ It is the result of first pass system identification for the derpy robot. The
 """
 import math
 
+import os,  inspect
+currentdir = os.path.dirname(os.path.abspath(inspect.getfile(inspect.currentframe())))
+parentdir = os.path.dirname(os.path.dirname(currentdir))
+os.sys.path.insert(0,parentdir)
+
 import numpy as np
-import minitaur
+from pybullet_envs.minitaur.envs  import minitaur
 
 KNEE_CONSTRAINT_POINT_LONG = [0, 0.0055, 0.088]
 KNEE_CONSTRAINT_POINT_SHORT = [0, 0.0055, 0.100]