Adding Tarantool queue backend

[ivasio]

Seems like it's time to start working on Tarantool queue implementation. I propose the following : a top-level Queue abstract class with general methods (put, get) and RedisQueue and TarantoolQueue classes in corresponding folders. RedisQueue is actually now implemented, making it compatible with abstract parent class would cost nothing

[code-of-kpp]

In python abstract classes usually don't serve any good role except for documentation. And they suck as manuals. So the best things we can have here is duck typing, README and tests (to ensure interface compatibility among other things)

[ivasio]

OK, I see. It might be the best moment to use some patterns and other OOP practices but after all duck typing coul be better

[ivasio]

I found an interesting lib that could be the basis for our Tarantool implementation https://github.com/shveenkov/aiotarantool-queue-python . The lib is authored by a Mail.ru dev, it may be a good way to go assuming Tarantool itself is being developed by this company
What could done as far as I can see is first of all refactoring the asyncio code in the fresh standard flavour (await instead of yield from, async def instead of @asyncio.coroutine etc). Need some time to dive into the sources deeper to find other things for possible improvement

[mesher-x]

shveenkov/aiotarantool#20
shveenkov/aiotarantool-queue-python#8

[code-of-kpp]

Ok, so both of them are merged and both libraries are compatible now