bump codegen crate to 0.2.4
bump codegen crate to 0.2.4

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