created project for lesson #6 homework
created Payable interface
added Person class
added Contractor & Employee classes
added main application class
filling workers array and inerating over it
implemented increasePay method for Contractor & Employee
Merge branch 'lesson_6'

* lesson_6:
  implemented increasePay method for Contractor & Employee
  filling workers array and inerating over it
  added main application class
  added Contractor & Employee classes
  added Person class
  created Payable interface
  created project for lesson #6 homework