Fix spelling and use key assignment for dictonary.
Fix spelling and use key assignment for dictonary.

minrk/dockerspawner,quantopian/dockerspawner,betatim/dockerspawner,ibab/dockerspawner,jlamcanopy/dockerspawner,quantopian/dockerspawner,jupyter/dockerspawner,anaderi/dockerspawner,Fokko/dockerspawner,Fokko/dockerspawner,jupyter/dockerspawner,jhamrick/dockerspawner,jhamrick/dockerspawner,Xarthisius/dockerspawner,Xarthisius/dockerspawner,betatim/dockerspawner,anaderi/dockerspawner,ibab/dockerspawner,minrk/dockerspawner,jlamcanopy/dockerspawner