pybullet a bit more refactoring, moving around files.

pybullet: move data to pybullet_data package, with getDataPath() method

examples/pybullet/gym/pybullet_envs/baselines/train_pybullet_cartpole.py

@@ -0,0 +1,39 @@
+#add parent dir to find package. Only needed for source code build, pip install doesn't need it.
+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 gym
+from pybullet_envs.bullet.cartpole_bullet import CartPoleBulletEnv
+
+from baselines import deepq
+
+
+def callback(lcl, glb):
+    # stop training if reward exceeds 199
+    is_solved = lcl['t'] > 100 and sum(lcl['episode_rewards'][-101:-1]) / 100 >= 199
+    return is_solved
+
+
+def main():
+	
+    env = CartPoleBulletEnv(renders=False)
+    model = deepq.models.mlp([64])
+    act = deepq.learn(
+        env,
+        q_func=model,
+        lr=1e-3,
+        max_timesteps=100000,
+        buffer_size=50000,
+        exploration_fraction=0.1,
+        exploration_final_eps=0.02,
+        print_freq=10,
+        callback=callback
+    )
+    print("Saving model to cartpole_model.pkl")
+    act.save("cartpole_model.pkl")
+
+
+if __name__ == '__main__':
+    main()