fix(session): case-insensitive user lookup via e-mail on keystone.session.signin()
fix(session): case-insensitive user lookup via e-mail on keystone.session.signin()

Closes Issue #1323

BlakeRxxk/keystone,developer-prosenjit/keystone,suryagh/keystone,Redmart/keystone,matthewstyers/keystone,vokal/keystone,benkroeger/keystone,dryna/keystone-twoje-urodziny,woody0907/keystone,WingedToaster/keystone,woody0907/keystone,andreufirefly/keystone,ONode/keystone,cermati/keystone,jacargentina/keystone,MORE-HEALTH/keystone,mikaoelitiana/keystone,qwales1/keystone,matthewstyers/keystone,trentmillar/keystone,jacargentina/keystone,everisARQ/keystone,danielmahon/keystone,concoursbyappointment/keystoneRedux,mbayfield/keystone,trystant/keystone,kloudsio/keystone,vokal/keystone,trentmillar/keystone,mbayfield/keystone,akoesnan/keystone,pr1ntr/keystone,benkroeger/keystone,webteckie/keystone,alobodig/keystone,kristianmandrup/keystone,snowkeeper/keystone,frontyard/keystone,codevlabs/keystone,omnibrain/keystone,w01fgang/keystone,tomasztunik/keystone,kloudsio/keystone,WofloW/keystone,creynders/keystone,rafmsou/keystone,sarriaroman/keystone,ligson/keystone,linhanyang/keystone,antonj/keystone,gcortese/keystone,dvdcastro/keystone,riyadhalnur/keystone,beni55/keystone,tomasztunik/keystone,SlashmanX/keystone,tanbo800/keystone,kidaa/keystone,lastjune/keystone,francesconero/keystone,webteckie/keystone,the1sky/keystone,michaelerobertsjr/keystone,wustxing/keystone,Pylipala/keystone,Freakland/keystone,concoursbyappointment/keystoneRedux,matthewstyers/keystone,beni55/keystone,stunjiturner/keystone,suryagh/keystone,dryna/keystone-twoje-urodziny,andrewlinfoot/keystone,asifiqbal84/keystone,stunjiturner/keystone,efernandesng/keystone,lojack/keystone,ONode/keystone,matthieugayon/keystone,gemscng/keystone,mekanics/keystone,trentmillar/keystone,SJApps/keystone,Adam14Four/keystone,ratecity/keystone,geminiyellow/keystone,efernandesng/keystone,joerter/keystone,naustudio/keystone,danielmahon/keystone,alobodig/keystone,davibe/keystone,kwangkim/keystone,pswoodworth/keystone,gemscng/keystone,omnibrain/keystone,snowkeeper/keystone,mekanics/keystone,codevlabs/keystone,douglasf/keystone,qwales1/keystone,Adam14Four/keystone,DenisNeustroev/keystone,magalhas/keystone,SlashmanX/keystone,kumo/keystone,MORE-HEALTH/keystone,w01fgang/keystone,wmertens/keystone,jeffreypriebe/keystone,danielmahon/keystone,Tangcuyu/keystone,stosorio/keystone,joerter/keystone,pr1ntr/keystone,matthieugayon/keystone,asifiqbal84/keystone,magalhas/keystone,frontyard/keystone,Redmart/keystone,douglasf/keystone,belafontestudio/keystone,rafmsou/keystone,michaelerobertsjr/keystone,kumo/keystone,creynders/keystone,geminiyellow/keystone,Pylipala/keystone,chrisgornall/d29blog,dvdcastro/keystone,jrit/keystone,Tangcuyu/keystone,Yaska/keystone,ratecity/keystone,chrisgornall/d29blog,udp/keystone,jstockwin/keystone,youprofit/keystone,kwangkim/keystone,sendyhalim/keystone,lojack/keystone,Ftonso/keystone,mikaoelitiana/keystone,Freakland/keystone,lastjune/keystone,wmertens/keystone,andrewlinfoot/keystone,andrewlinfoot/keystone,ligson/keystone,cermati/keystone,jrit/keystone,naustudio/keystone,nickhsine/keystone,SJApps/keystone,Yaska/keystone,onenorth/keystone,vokal/keystone,stosorio/keystone,antonj/keystone,everisARQ/keystone,sendyhalim/keystone,youprofit/keystone,DenisNeustroev/keystone,wustxing/keystone,pswoodworth/keystone,onenorth/keystone,gcortese/keystone,udp/keystone,kidaa/keystone,riyadhalnur/keystone,francesconero/keystone,unsworn/keystone,sarriaroman/keystone,jeffreypriebe/keystone,WofloW/keystone,jstockwin/keystone,developer-prosenjit/keystone,vmkcom/keystone,Pop-Code/keystone,brianjd/keystone,xyzteam2016/keystone,benkroeger/keystone,kristianmandrup/keystone,Yaska/keystone,xyzteam2016/keystone,the1sky/keystone,nickhsine/keystone,brianjd/keystone,Ftonso/keystone,trystant/keystone,belafontestudio/keystone,tony2cssc/keystone,vmkcom/keystone,Pop-Code/keystone,BlakeRxxk/keystone,andreufirefly/keystone,naustudio/keystone,frontyard/keystone,akoesnan/keystone,davibe/keystone,tanbo800/keystone,WingedToaster/keystone,unsworn/keystone,tony2cssc/keystone