v0.3.4

• add getProjectDuration getter in README.md file
• add detailed description in README.md for pushScreen method of ProjectData class
• add new MissingOrderError class
• implement ProjectDataUtil class with normalizeOrders, sortFactory, insertScreenAtOrder and
  insertAndNormalizeOrder methods
• add pushScreen method to ProjectData class
• update update-project-data-partial-advanced example