refactor: remove the policyPort option

This option was used by the flash-websocket transport.

README.md

@@ -236,7 +236,6 @@ Exposed as `eio` in the browser standalone build.
         transport request. Note: polling requests are always stamped unless this
         option is explicitly set to `false` (`false`)
       - `timestampParam` (`String`): timestamp parameter (`t`)
-      - `policyPort` (`Number`): port the policy server listens on (`843`)
       - `path` (`String`): path to connect to, default is `/engine.io`
       - `transports` (`Array`): a list of transports to try (in order).
       Defaults to `['polling', 'websocket']`. `Engine`

lib/socket.js

@@ -65,7 +65,6 @@ class Socket extends Emitter {
         upgrade: true,
         jsonp: true,
         timestampParam: "t",
-        policyPort: 843,
         rememberUpgrade: false,
         rejectUnauthorized: true,
         perMessageDeflate: {