Fixes package configuration for SPM.
Fixes package configuration for SPM.

ReactiveX/RxSwift,cfraz89/RxSwift,kzaher/RxSwift,tottakai/RxSwift,KyoheiG3/RxSwift,KyoheiG3/RxSwift,ReactiveX/RxSwift,hsoi/RxSwift,tottakai/RxSwift,shiratsu/RxSwift,KyoheiG3/RxSwift,ReactiveX/RxSwift,cfraz89/RxSwift,kzaher/RxSwift,shiratsu/RxSwift,thanegill/RxSwift,kzaher/RxSwift,tottakai/RxSwift,cfraz89/RxSwift,hsoi/RxSwift,thanegill/RxSwift,hsoi/RxSwift,kzaher/RxSwift,hsoi/RxSwift,shiratsu/RxSwift,cfraz89/RxSwift,thanegill/RxSwift,thanegill/RxSwift