add Directory Service integration tests
add Directory Service integration tests

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