Define a proper location for env file with configuration

[erodrigufer]

Define a proper location for an env file with configuration variables for the application.

It could be placed at $HOME/.config or at /usr/local/bin/ctfsmd. I do not know yet precisely what location would be best, or if it even makes sense to publish some exemplary env. files to the repository.

As of v0.2.0 the system always returns an error when deploying because it does not find an .env file. This problem should also be resolved (see cli package).