refactoring; added comment to Dockerfile on what needs tzdata package
refactoring; added comment to Dockerfile on what needs tzdata package

byran/cyber-dojo-web,cyber-dojo/web,byran/cyber-dojo-web,byran/cyber-dojo-web,byran/cyber-dojo-web,cyber-dojo/web,byran/cyber-dojo-web,cyber-dojo/web,byran/cyber-dojo-web,cyber-dojo/web,byran/cyber-dojo-web,byran/cyber-dojo-web,byran/cyber-dojo-web