Fix RubyMoney/Money i18n deprecation warning

[jacobherrington]

This PR fixes the warning message coming from RubyMoney/money discussed in RubyMoney/money#816

[DEPRECATION] `use_i18n` is deprecated - use `Money.locale_backend = :i18n` instead

It might be worth waiting to see if this is fixed in the money gem before we merge this PR.

[jacobherrington]

😭

[kennyadsl]

As far as I get from this comment in the issue on RubyMoney/money, you have to set that configuration up in each application. I'm not sure that initializer works but setting that here it removes the deprecations in specs. I think we need to put that setting in a place where it is also configurable by users with the other Spree::Money configurations.

[jacobherrington]

That might be a better solution, although this does fix it when I run tests which was what I was trying to fix. I'll try to make it a configuration option instead though.

[tvdeyen]

I think we need to put that setting in a place with is also configurable by users with the other Spree::Money configurations.

Yes, I agree. There is also money-rails that has an install generator, that creates the above mentioned initializer in the host app. Although I don't like to add another dependency, I think we should at least consider it or implement our own generator during Solidus install.

[jacobherrington]

Work is being done on #2912