Add enable_testability to IterableSDK

Author: tapashmajumder

swift-sdk.xcodeproj/project.pbxproj

@@ -1275,6 +1275,7 @@
 				DYLIB_COMPATIBILITY_VERSION = 1;
 				DYLIB_CURRENT_VERSION = 1;
 				DYLIB_INSTALL_NAME_BASE = "@rpath";
+				ENABLE_TESTABILITY = YES;
 				INFOPLIST_FILE = "swift-sdk/Info.plist";
 				INSTALL_PATH = "$(LOCAL_LIBRARY_DIR)/Frameworks";
 				IPHONEOS_DEPLOYMENT_TARGET = 9.0;