Merge branch 'develop' into 'check-style'

# Conflicts:
#   destination-module/src/main/java/cz/muni/fi/pa165/airportmanager/destinationmodule/data/model/Destination.java
#   flight-module/src/main/java/cz/muni/fi/pa165/airportmanager/flightmodule/data/repository/FlightRepository.java
#   steward-module/src/main/java/cz/muni/fi/pa165/airportmanager/stewardmodule/rest/StewardController.java