Education project (homework) for High Load Architect OTUS course
-e <host>:<port>
e.g.: -e 0.0.0.0:80
default: 0.0.0.0:8181
-d <user>:<password>@<host>/<database name>
e.g.: -d 'admin:admin@localhost/social_network'
default: admin:admin@localhost/social_network
-r <user>:<password>@<host>/<database name>
e.g.: -r 'admin:admin@localhost/social_network'
default: when the option is omitted, app uses the DB which is specified in d