Update create_account to use python3

Redesign RabbitMQ - This PR adds a fan-out architecture for rabbitmq_agents 

add email field
if email not given, will:
    1. use username + domain
    2. use username (XIAS account)

Using rc_util functions to send request message
 and subscribe for confirmation right after that

Since publish doesn't have to do binding,
 separate binding make it cleaner and less trouble

user should explicitly call disconnect
Modify README regarding explicity disconnect call

Change to only one exchange, so there's only one instance, rc_rmq

Remove trailing whitespace
Add space between '+'

publish funtion:
 only make connection if it is not yet established
 only disconnect if there's no consumer using the same connection

consume function:
 only make connection if it is not yet established
 adding _consuming variable to keep tracking if the connection needs to be alive

Feat connection module

After standup meeting, change the exchange name to Register