Test for issue with Fallbacks and enforce_available_locales
Test for issue with Fallbacks and enforce_available_locales

Created a test-case for an issue where the
Fallbacks module will generate an
I18n::InvalidLocale error.

Fallbacks relies on I18n.translation to find out
whether there's a translation for a fallback
locale (e.g. :'de' for :'de-DE'). But
I18n.translation does not distinguish from a
"user" call and one coming from the Fallbacks
module, and may raise I18n::InvalidLocale if
enforce_available_locales is set.

jay3126/i18n-custom,lypanov/i18n,PikachuEXE/i18n,godaddy/i18n,tenderlove/i18n,Bartuz/i18n,daniel-rikowski/i18n,viniciusnz/i18n,xchanging-mm4/i18n,ducthanh/i18n,iamjarvo/i18n,svenfuchs/i18n,benternet/i18n