Added None to empty returns for consistency and removed ending return Nones - again consistency.
Added None to empty returns for consistency and removed ending return Nones - again consistency.

iamrudra/elastalert,dvopsway/elastalert,jetyang2005/elastalert,rprabhat/elastalert,jetyang2005/elastalert,Yelp/elastalert,ltagliamonte/elastalert,jetyang2005/elastalert