Implement missing 3 and 4 room plots in Ogre_city_report.pdf in pdf_creator.py

[vfedotovs]

Missing:
2 # generating and saving charts to files for Size_sqm/Price_in_eur relationships
1 # FIXME move to function that has for loop with range 4 that creates 4 png files + allroom.png file
45 create_png_plot(all_rooms_data_frame, 'Size_sqm', "Price_in_eur",
1 "All 1-4 room apartments", '1-4_rooms.png')
2 create_png_plot(one_room_df, 'Size_sqm', "Price_in_eur",
3 "Single room apartments", '1_rooms.png')
4 create_png_plot(two_room_df, 'Size_sqm', "Price_in_eur",
5 "Double room apartments", '2_rooms.png')