message: fix(GUI): correct relative notification icon path
  We update the relative icon path to the correct relative path containing
  the Etcher icon.
  See:
diff: @@ -60,6 +60,8 @@ module.exports = function(
  // otherwise Windows throws EPERM
  DriveScannerService.stop();
  + const iconPath = '../../assets/icon.png';
  +
  ImageWriterService.flash(image.path, drive).then(() => {
  if (!flashState.wasLastFlashCancelled()) {
  notification.send('Success!', {
  @@ -67,7 +69,7 @@ module.exports = function(
  imageBasename: path.basename(image.path),
  drive
  }),
  - icon: '../../../../../assets/icon.png'
  + icon: iconPath
  });
  $state.go('success');
  }
  @@ -78,7 +80,7 @@ module.exports = function(
  imageBasename: path.basename(image.path),
  drive
  }),
  - icon: '../../../../../assets/icon.png'
  + icon: iconPath
  });
  // TODO: All these error codes to messages translations
  