Elefant docker support

[lux]

Adds basic docker configurations for development and production environments, and a makefile for building them. To generate a production container named elefant, run:

$ make build

To make a development container named elefant-dev, run:

$ make dev

To spin up a development environment with a MySQL database and a Redis instance for caching, run:

$ make run

And to shut it down afterward, run:

$ make down

See docker-compose.yml and .docker/* for more info.

[evan70]

Nice :) Thanks