USERGRID-3025: added QuartCore.framework to README.
USERGRID-3025: added QuartCore.framework to README.

pauldardeau/apigee-ios-sdk,apigee/apigee-ios-sdk,RobertWalsh/apigee-ios-sdk,pauldardeau/apigee-ios-sdk,pauldardeau/apigee-ios-sdk,RobertWalsh/apigee-ios-sdk,developerdave/apigee-ios-sdk,developerdave/apigee-ios-sdk,apigee/apigee-ios-sdk,RobertWalsh/apigee-ios-sdk,pauldardeau/apigee-ios-sdk,apigee/apigee-ios-sdk,developerdave/apigee-ios-sdk,developerdave/apigee-ios-sdk,RobertWalsh/apigee-ios-sdk,developerdave/apigee-ios-sdk,RobertWalsh/apigee-ios-sdk,RobertWalsh/apigee-ios-sdk,developerdave/apigee-ios-sdk,apigee/apigee-ios-sdk,apigee/apigee-ios-sdk,apigee/apigee-ios-sdk