Merge branch 'ttpwa-004' into 'development'

Fixes and tidying up the server side of the sockets

See merge request martind2000/traintimesPWA!12

server/lib/twitter.js

@@ -74,7 +74,7 @@ exports.updates = (newEmitter) => {
   eventEmitter = newEmitter;
   buildList();
   
-  setInterval(() => {
+  setTimeout(() => {
     startTweetUpdates();  
   }, 30000);
 };