Fukász Rómeó Ervin / cloud

Change Celery result backend to memcached #119

Moving result backend to memchached.

🆗 Celery configurations
🆗 Docs
🚧 Testing

Install:

* `sudo apt-get install memcached libmemcached-dev`
* `pip install -r requirements/base.txt`  (`pip install pylibmc`)
* ⚠  update ALL virtualenvs and their config: `export CACHE_URI='pylibmc://127.0.0.1:11211/'`