testing number of signatures correct to make sure struct returned by GetAllTargetMetadataByName contains signatures
testing number of signatures correct to make sure struct returned by GetAllTargetMetadataByName contains signatures

Signed-off-by: Avi Vaid <5d848571eb53d86b5530128c4fd3edd4d2c88399@gmail.com>

docker/notary,andrewhsu/notary,johnsandiford/notary,jfrazelle/notary,endophage/notary,docker/notary,umayr/notary,HuKeping/notary,andrewhsu/notary,docker/notary,johnsandiford/notary,dqminh/notary,dqminh/notary,vdemeester/notary,endophage/notary,jfrazelle/notary,HuKeping/notary,umayr/notary,HuKeping/notary,vdemeester/notary,johnsandiford/notary,vdemeester/notary,dqminh/notary,umayr/notary,jfrazelle/notary,endophage/notary,andrewhsu/notary