Fix bug that weber can't find locale files.

[tmaeda]

When I ran start.sh of exmaples/SimpleChat, I got following error.

** Reason for termination ==
** {{'Elixir.File.Error','__exception__',enoent,<<"read file">>,
        <<"/Users/xxx/rpm/SOURCES/weber/examples/SimpleChat/deps/weber/lib/weber/i18n/localization/localeen_US.json">>},
    [{'Elixir.File','read!',1,[{file,"lib/file.ex"},{line,205}]},
     {'Elixir.Weber.Localization.LocalizationManager',apply_on_file,3,
         [{file,"lib/weber/i18n/localization_manager.ex"},{line,54}]},
     {'Elixir.Enum','-each/2-lists^foreach/1-0-',2,
         [{file,"lib/enum.ex"},{line,517}]},
     {'Elixir.Enum',each,2,[{file,"lib/enum.ex"},{line,517}]},
     {'Elixir.Weber.Localization.LocalizationManager',handle_cast,2,
         [{file,"lib/weber/i18n/localization_manager.ex"},{line,29}]},
     {gen_server,handle_msg,5,[{file,"gen_server.erl"},{line,604}]},
     {proc_lib,init_p_do_apply,3,[{file,"proc_lib.erl"},{line,239}]}]}