Xavi007: AtsushiSakai#903 There's an error in the transformation_matr…

…ix of Quadrotor renamed "yaw" to "roll" (AtsushiSakai#906)

AerialNavigation/drone_3d_trajectory_following/Quadrotor.py

@@ -56,7 +56,7 @@ def transformation_matrix(self):
             [[cos(yaw) * cos(pitch), -sin(yaw) * cos(roll) + cos(yaw) * sin(pitch) * sin(roll), sin(yaw) * sin(roll) + cos(yaw) * sin(pitch) * cos(roll), x],
              [sin(yaw) * cos(pitch), cos(yaw) * cos(roll) + sin(yaw) * sin(pitch)
               * sin(roll), -cos(yaw) * sin(roll) + sin(yaw) * sin(pitch) * cos(roll), y],
-             [-sin(pitch), cos(pitch) * sin(roll), cos(pitch) * cos(yaw), z]
+             [-sin(pitch), cos(pitch) * sin(roll), cos(pitch) * cos(roll), z]
              ])
 
     def plot(self):  # pragma: no cover