Updated podfile to iOS client 2.0.0 a3
Updated podfile to iOS client 2.0.0 a3

Lightstreamer/Lightstreamer-example-Chat-client-ios-swift,Weswit/Lightstreamer-example-Chat-client-ios-swift,Lightstreamer/Lightstreamer-example-Chat-client-ios-swift,Weswit/Lightstreamer-example-Chat-client-ios-swift