refactor main-app process

clean unnecessary codes

lib/finder-window.js

@@ -1,4 +1,5 @@
 const electron = require('electron')
+const { app } = electron
 const BrowserWindow = electron.BrowserWindow
 const Menu = electron.Menu
 const MenuItem = electron.MenuItem
@@ -44,7 +45,7 @@ finderWindow.on('close', function (e) {
 })
 
 var appIcon = new Tray(path.join(__dirname, '../resources/tray-icon.png'))
-appIcon.setToolTip('Boost')
+appIcon.setToolTip('Boostnote')
 
 var trayMenu = new Menu()
 trayMenu.append(new MenuItem({
@@ -84,4 +85,9 @@ function hideFinder () {
   }
   finderWindow.hide()
 }
+
+app.on('before-quit', function (e) {
+  finderWindow.removeAllListeners()
+})
+
 module.exports = finderWindow