Constant structs do not work. #10

const SubStruct CONST_SUBSTRUCT = { "sub_id": 9, "sub_name": "number nine" }

$ THRIFT_INPUT_DIR=test/ mix compile.thrift
thrift -o src --gen erl test/thrash_test.thrift

$ mix test
Compiling 1 file (.erl)
Compiling 11 files (.ex)

== Compilation error on file test/simple_struct.ex ==
** (ErlangError) erlang error: {:undefined_record, :SubStruct}
    (stdlib) :erl_eval.exprs/2
    expanding macro: Thrash.Constants.__using__/1
    test/simple_struct.ex:14: Constants (module)
    (elixir) expanding macro: Kernel.use/1
    test/simple_struct.ex:14: Constants (module)