Coordinates

Coordinates classes

`skrobot.coordinates.Coordinates`	Coordinates class to manipulate rotation and translation.
`skrobot.coordinates.CascadedCoords`

`skrobot.coordinates.geo.midcoords`	Returns mid (or p) coordinates of given two coordinates c1 and c2.
`skrobot.coordinates.geo.orient_coords_to_axis`	Orient axis to the direction
`skrobot.coordinates.base.random_coords`	Return Coordinates class has random translation and rotation
`skrobot.coordinates.base.coordinates_distance`
`skrobot.coordinates.base.transform_coords`	Return Coordinates by applying c1 to c2 from the left