Use importlib instead of imp.
Use importlib instead of imp.

This allows DJANGO_SETTINGS_MODULE with dots, for example
DJANGO_SETTINGS_MODULE=sites.dev.settings_mkt

kumar303/addons-server,jamesthechamp/zamboni,mudithkr/zamboni,diox/olympia,mozilla/olympia,ddurst/zamboni,wagnerand/olympia,mozilla/zamboni,wagnerand/zamboni,psiinon/addons-server,diox/zamboni,diox/olympia,robhudson/zamboni,robhudson/zamboni,ingenioustechie/zamboni,mstriemer/olympia,mozilla/addons-server,mstriemer/olympia,andymckay/addons-server,harry-7/addons-server,mozilla/addons-server,jpetto/olympia,Nolski/olympia,Joergen/olympia,yfdyh000/olympia,kmaglione/olympia,Joergen/zamboni,harikishen/addons-server,kumar303/zamboni,ngokevin/zamboni,mdaif/olympia,eviljeff/olympia,kumar303/addons-server,psiinon/addons-server,kmaglione/olympia,Witia1/olympia,mstriemer/addons-server,aviarypl/mozilla-l10n-addons-server,washort/zamboni,Joergen/olympia,tsl143/zamboni,andymckay/olympia,wagnerand/olympia,harry-7/addons-server,harry-7/addons-server,Joergen/zamboni,koehlermichael/olympia,diox/zamboni,ddurst/zamboni,diox/olympia,eviljeff/olympia,Revanth47/addons-server,luckylavish/zamboni,eviljeff/zamboni,kumar303/addons-server,mdaif/olympia,andymckay/olympia,clouserw/zamboni,ayushagrawal288/zamboni,andymckay/olympia,jpetto/olympia,kumar303/olympia,beni55/olympia,tsl143/addons-server,andymckay/addons-server,spasovski/zamboni,shahbaz17/zamboni,jpetto/olympia,spasovski/zamboni,ayushagrawal288/zamboni,johancz/olympia,ingenioustechie/zamboni,mozilla/zamboni,SuriyaaKudoIsc/olympia,mstriemer/addons-server,jasonthomas/zamboni,ngokevin/zamboni,SuriyaaKudoIsc/olympia,Joergen/zamboni,Hitechverma/zamboni,ayushagrawal288/zamboni,mozilla/addons-server,andymckay/zamboni,SuriyaaKudoIsc/olympia,crdoconnor/olympia,tsl143/addons-server,muffinresearch/addons-server,aviarypl/mozilla-l10n-addons-server,ingenioustechie/zamboni,tsl143/zamboni,kumar303/zamboni,mstriemer/zamboni,Jobava/zamboni,Hitechverma/zamboni,wagnerand/zamboni,psiinon/addons-server,Nolski/olympia,mstriemer/addons-server,eviljeff/zamboni,kmaglione/olympia,washort/zamboni,magopian/olympia,tsl143/zamboni,muffinresearch/olympia,bqbn/addons-server,mozilla/zamboni,yfdyh000/olympia,magopian/olympia,elysium001/zamboni,mozilla/olympia,kmaglione/olympia,johancz/olympia,yfdyh000/olympia,beni55/olympia,Joergen/zamboni,kumar303/olympia,wagnerand/olympia,mstriemer/olympia,spasovski/zamboni,Revanth47/addons-server,ayushagrawal288/zamboni,yfdyh000/olympia,diox/olympia,bqbn/addons-server,robhudson/zamboni,diox/zamboni,mstriemer/olympia,jamesthechamp/zamboni,johancz/olympia,muffinresearch/olympia,wagnerand/zamboni,tsl143/addons-server,muffinresearch/addons-server,kumar303/addons-server,Joergen/olympia,mozilla/olympia,harikishen/addons-server,mrrrgn/olympia,tsl143/addons-server,atiqueahmedziad/addons-server,mudithkr/zamboni,elysium001/zamboni,Prashant-Surya/addons-server,magopian/olympia,mudithkr/zamboni,psiinon/addons-server,koehlermichael/olympia,kumar303/olympia,wagnerand/addons-server,wagnerand/olympia,anaran/olympia,beni55/olympia,lavish205/olympia,mozilla/zamboni,andymckay/addons-server,Joergen/olympia,Nolski/olympia,anaran/olympia,atiqueahmedziad/addons-server,Nolski/olympia,jpetto/olympia,eviljeff/olympia,Prashant-Surya/addons-server,muffinresearch/addons-server,atiqueahmedziad/addons-server,andymckay/addons-server,kumar303/olympia,wagnerand/addons-server,mozilla/addons-server,shahbaz17/zamboni,mrrrgn/olympia,crdoconnor/olympia,mrrrgn/olympia,Nolski/olympia,lavish205/olympia,Hitechverma/zamboni,wagnerand/addons-server,mstriemer/zamboni,magopian/olympia,anaran/olympia,mdaif/olympia,lavish205/olympia,kumar303/zamboni,Jobava/zamboni,lavish205/olympia,robhudson/zamboni,shahbaz17/zamboni,atiqueahmedziad/addons-server,muffinresearch/olympia,johancz/olympia,kumar303/zamboni,luckylavish/zamboni,ddurst/zamboni,andymckay/olympia,Revanth47/addons-server,muffinresearch/addons-server,crdoconnor/olympia,eviljeff/zamboni,shahbaz17/zamboni,tsl143/zamboni,beni55/olympia,beni55/olympia,clouserw/zamboni,luckylavish/zamboni,andymckay/zamboni,crdoconnor/olympia,jasonthomas/zamboni,andymckay/zamboni,wagnerand/addons-server,wagnerand/zamboni,muffinresearch/olympia,mozilla/olympia,Prashant-Surya/addons-server,bqbn/addons-server,harikishen/addons-server,washort/zamboni,muffinresearch/addons-server,Witia1/olympia,elysium001/zamboni,magopian/olympia,Prashant-Surya/addons-server,Hitechverma/zamboni,mdaif/olympia,harikishen/addons-server,spasovski/zamboni,luckylavish/zamboni,Jobava/zamboni,ddurst/zamboni,clouserw/zamboni,Joergen/zamboni,ngokevin/zamboni,eviljeff/zamboni,diox/zamboni,Revanth47/addons-server,jasonthomas/zamboni,Joergen/olympia,anaran/olympia,koehlermichael/olympia,Witia1/olympia,johancz/olympia,mstriemer/zamboni,koehlermichael/olympia,mstriemer/zamboni,crdoconnor/olympia,aviarypl/mozilla-l10n-addons-server,Witia1/olympia,eviljeff/olympia,mrrrgn/olympia,mudithkr/zamboni,harry-7/addons-server,Joergen/zamboni,yfdyh000/olympia,ingenioustechie/zamboni,SuriyaaKudoIsc/olympia,aviarypl/mozilla-l10n-addons-server,jamesthechamp/zamboni,mrrrgn/olympia,Jobava/zamboni,mstriemer/addons-server,Witia1/olympia,mdaif/olympia,jamesthechamp/zamboni,muffinresearch/olympia,kmaglione/olympia,clouserw/zamboni,bqbn/addons-server,washort/zamboni,jasonthomas/zamboni,elysium001/zamboni,koehlermichael/olympia