Models and authenticator refactor

Closes #27

See merge request !28

Commented testGetMovies, because it used prod DB, which is populated with...

See merge request !27

Resolve "Setup docker"

See merge request !26

Resolve "Tests for movies and images"

See merge request !20

Added test for login module

See merge request !25

# Conflicts:
#	core/src/main/java/cz/muni/fi/pa165/user/UserController.java
#	core/src/main/java/cz/muni/fi/pa165/user/UserService.java

Commented testGetMovies, because it used prod DB, which is populated with testCreateMovie -> will be fixed when repository mock is used