#78 Make the error messages obvious for troubleshooting issues

[noureddine]

It would be helpful for users if the error messages are obvious. As example I got this error message
2018-02-20 14:37:27,661 [ERROR] AMQP Sender cannot connect to: <hostname.....>
2018-02-20 14:37:27,662 [ERROR] Type=<class 'unboundlocalerror'="">, Value=local variable 'msg' referenced before assignment
This error did not help to troubleshoot the issue. I had to check the code to figure out the issue was the connection and I had to change the subscriber config to use amqps instead of amqp. </class></hostname.....>

[psilva]

this was fixed.