Added SWAP to ISWAP gate conversion in resolve_gates
Added SWAP to ISWAP gate conversion in resolve_gates

cgranade/qutip,anubhavvardhan/qutip,cgranade/qutip,zasdfgbnm/qutip,qutip/qutip,zasdfgbnm/qutip,qutip/qutip,anubhavvardhan/qutip