HWIA relies on Hash#symbolize_keys and #stringify_keys extensions.

Signed-off-by: NJeremy Kemper <jeremy@bitsweat.net>

activesupport/lib/active_support/hash_with_indifferent_access.rb

+require 'active_support/core_ext/hash/keys'
+
 # This class has dubious semantics and we only have it so that
 # people can write params[:key] instead of params['key']
 # and they get the same value for both keys.