fix yargs error and upgrade dependencies

Author: Samantha Chalker

lib/argv.js

@@ -42,7 +42,7 @@ module.exports = (version='') => {
       .boolean('rejectUnauthorized')
       .describe('rejectUnauthorized', 'Reject all unauthorized certificates upon connection')
       .help('help', 'Show help menu')
-      .version(() => version)
+      .version(version)
       .alias('version', 'v')
       .example('wssip -p 8081 -s', 'listen on localhost:8081 and autostart the proxy')
       .example('wssip --timeout 30', 'wait 30 seconds for page load before stopping')