Redis is not optional

[f4exb]

Even with "authentication" : false and "dynamicRooms" : false Redis server is required, else the server does not start and fails with this message:

npm start

> symple@1.0.8 start /opt/build/symple/symple-server
> node server.js

Symple server listening on port 4500
events.js:183
      throw er; // Unhandled 'error' event
      ^

Error: Redis connection to localhost:6379 failed - connect ECONNREFUSED 127.0.0.1:6379
    at Object._errnoException (util.js:1022:11)
    at _exceptionWithHostPort (util.js:1044:20)
    at TCPConnectWrap.afterConnect [as oncomplete] (net.js:1198:14)
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! symple@1.0.8 start: `node server.js`
npm ERR! Exit status 1
npm ERR! 
npm ERR! Failed at the symple@1.0.8 start script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR!     /home/f4exb/.npm/_logs/2019-02-10T12_10_13_514Z-debug.log

It should either be made optional effectively or the documentation in the readme.md changed.