fix(travis): Up the socket timeout 2->20s. (#3103)

Log something on all disconnect() calls.
Up the timeout as suggested by ndcornelius@ on #3102

Author: johnjbarton

client/main.js

@@ -14,7 +14,7 @@ var KARMA_PROXY_PATH = constants.KARMA_PROXY_PATH
 var socket = io(location.host, {
   reconnectionDelay: 500,
   reconnectionDelayMax: Infinity,
-  timeout: 2000,
+  timeout: 20000,
   path: KARMA_PROXY_PATH + KARMA_URL_ROOT.substr(1) + 'socket.io',
   'sync disconnect on unload': true
 })

lib/browser.js

@@ -151,15 +151,15 @@ class Browser {
     }
 
     if (this.state === CONNECTED) {
-      this.disconnect()
+      this.disconnect('client disconnected from CONNECTED state')
     } else if (this.state === CONFIGURING || this.state === EXECUTING) {
       this.log.debug('Disconnected during run, waiting %sms for reconnecting.', this.disconnectDelay)
       this.state = EXECUTING_DISCONNECTED
 
       this.pendingDisconnect = this.timer.setTimeout(() => {
         this.lastResult.totalTimeEnd()
         this.lastResult.disconnected = true
-        this.disconnect()
+        this.disconnect(`reconnect failed before timeout of ${this.disconnectDelay}ms`)
         this.emitter.emit('browser_complete', this)
       }, this.disconnectDelay)