fix a few pybullet Gym environments for rendering in stable_baselines

if PYBULLET_EGL environment is set, try to enable EGL for faster rendering
bump up pybullet to 2.6.2

setup.py

@@ -491,7 +491,7 @@ if 'BT_USE_EGL' in EGL_CXX_FLAGS:
 
 setup(
     name='pybullet',
-    version='2.6.1',
+    version='2.6.2',
     description=
     'Official Python Interface for the Bullet Physics SDK specialized for Robotics Simulation and Reinforcement Learning',
     long_description=
@@ -505,6 +505,9 @@ setup(
         'game development', 'virtual reality', 'physics simulation', 'robotics',
         'collision detection', 'opengl'
     ],
+    install_requires=[
+          'numpy',
+    ],
     ext_modules=extensions,
     classifiers=[
         'Development Status :: 5 - Production/Stable',