fix pybullet racecarGymEnv to use thread-safe pybullet

examples/pybullet/gym/pybullet_envs/examples/racecarGymEnvTest.py

@@ -5,8 +5,8 @@ parentdir = os.path.dirname(os.path.dirname(currentdir))
 os.sys.path.insert(0,parentdir)
 
 from pybullet_envs.bullet.racecarGymEnv import RacecarGymEnv
-print ("hello")
 environment = RacecarGymEnv(renders=True)
+environment.reset()
 
 targetVelocitySlider = environment._p.addUserDebugParameter("wheelVelocity",-1,1,0)
 steeringSlider = environment._p.addUserDebugParameter("steering",-0.5,0.5,0)