Add TypeScript declaration for ReconnectingWebSocket class.
Add TypeScript declaration for ReconnectingWebSocket class.

UIKit0/reconnecting-websocket,ekapujiw2002/reconnecting-websocket,nguarracino/reconnecting-websocket,hw1e14/reconnecting-websocket,mcanthony/reconnecting-websocket,joewalnes/reconnecting-websocket,futurist/reconnecting-websocket