Fixes up Cargo.toml to allow for codegen to be run at crate packaging time.
Fixes up Cargo.toml to allow for codegen to be run at crate packaging time.

ford-prefect/rusoto,noggleboggle/rusoto,SecurityInsanity/rusoto,mattico/rusoto,mattico/rusoto,DualSpark/rust-aws,mthjones/rusoto,mthjones/rusoto,rusoto/rusoto,cmsd2/rusoto,DualSpark/rust-aws,DualSpark/rusoto,rusoto/rusoto,mattico/rusoto,ford-prefect/rusoto,rusoto/rusoto,DualSpark/rusoto,DualSpark/rust-aws,indiv0/rusoto,SecurityInsanity/rusoto,DualSpark/rusoto