Convert hashes to hash with indifferent access for rails

[ashish91]

Deals with symbol keys in hash when translating values with I18n (Issue #627). This PR converts the hash to a hash with indifferent access in order to support string or symbol access.

This problem only arises in rails console which converts the hash keys into symbol. Here's an example:

Rails console
2.3.0 :001 > I18n.translate(*["faker.vehicle.manufacture", {:locale=>:en, :raise=>true}]).first
 => {:name=>"MARQUESS ELECTRIC CAR COMPANY", :wmi=>"15E", :wmi_ext=>nil}

IRB console
2.3.0 :003 > I18n.translate(*["faker.vehicle.manufacture", {:locale=>:en, :raise=>true}]).first
 => {"name"=>"MARQUESS ELECTRIC CAR COMPANY", "wmi"=>"15E", "wmi_ext"=>nil}