Add gym-pybullet-drones to third party environment list 
diff --git a/docs/environments.md b/docs/environments.md
index c4dd3b43d6d..271b9a61ae1 100644
--- a/docs/environments.md
+++ b/docs/environments.md
@@ -296,4 +296,10 @@ Learn more here: https://github.com/addy1997/Gridworld
 
 An environment for simulating the classical optimal control problem where the thrust of a vertically ascending rocket shall be determined such that it reaches the maximum possible altitude, while being subject to varying aerodynamic drag, gravity and mass. 
 
-Learn more here: https://github.com/osannolik/gym-goddard
\ No newline at end of file
+Learn more here: https://github.com/osannolik/gym-goddard
+
+### gym-pybullet-drones: Learning Quadcopter Control
+
+A simple environment using [PyBullet](http://github.com/bulletphysics/bullet3) to simulate the dynamics of a [Bitcraze Crazyflie 2.x](https://www.bitcraze.io/documentation/hardware/crazyflie_2_1/crazyflie_2_1-datasheet.pdf) nanoquadrotor
+
+Learn more here: https://github.com/JacopoPan/gym-pybullet-drones
\ No newline at end of file

3rd party quadcopter dynamics simulator