Aug 15 15, 11:51 PM | Last edited: Aug 16 15, 12:00 AM
Its already a thing. Press the b key.
EDIT: I thought you were asking just to veiw a players perspective; The b key let's you do that. Currently there is no way to edit the movement of a player. You can however set key frames in and out of spectator which can give you a little bit more control.