Release of 3.0.2

• Fixes setElement
• Added support for beforeContent and afterContent
  • http://vespakoen.github.io/menu/class-Menu.Items.Item.html#_setBeforeContent
  • http://vespakoen.github.io/menu/class-Menu.Items.Item.html#_setAfterContent
  • http://vespakoen.github.io/menu/class-Menu.Items.ItemList.html#_add
  • http://vespakoen.github.io/menu/class-Menu.Items.ItemList.html#_raw
  • http://vespakoen.github.io/menu/class-Menu.Items.ItemList.html#_addContent
• Added more PHP versions to travis config
• Added badges to the readme
• Rebuilt the API docs