Add publish confirms for mt messages
Improve test

After publish confirms appeared, each request became blocking.
To speed up tests, spawn_link was added for each test case.
At the moment test cases work in parallel
Use CC header to publish mt msgs

The greate deal of code that processed pair of publish
confirms id (the first for kelly queue and the second
for the just gtw queue) was replaced with via rabbitMQ
extention - CC header. This solution allowed to publish
msgs with single publish function call and also with
single publish confirm callback.
Cleanup
Refactor send sms request processing

There were a lot of code duplication, no stucture and sequence
of send sms request processing.
All of the send sms request processing code was replaced with
step by step processing. Hence, code duplication disappeared,
code became straightforward, extensible and maintained.