Introduce subscription set id field ana-174#177

SrikalaB merged 3 commits intomainchartmogul/chartmogul-ruby:mainfrom

srikala/ana-174-expose-subscription-set-external-id-in-list-activities-apichartmogul/chartmogul-ruby:srikala/ana-174-expose-subscription-set-external-id-in-list-activities-apiCopy head branch name to clipboard