chore(package): update css-loader to version 0.27.3
chore(package): update css-loader to version 0.27.3

Closes #1902

https://greenkeeper.io/

tsl143/addons-frontend,kumar303/addons-frontend,kumar303/addons-frontend,aviarypl/mozilla-l10n-addons-frontend,kumar303/addons-frontend,aviarypl/mozilla-l10n-addons-frontend,aviarypl/mozilla-l10n-addons-frontend,tsl143/addons-frontend,mozilla/addons-frontend,mozilla/addons-frontend,tsl143/addons-frontend,tsl143/addons-frontend,mozilla/addons-frontend,mozilla/addons-frontend,aviarypl/mozilla-l10n-addons-frontend,kumar303/addons-frontend