One of my original thoughts was to have the stored credentials in a predefined location within the users home directory, however it wasn't clear to me how this would work with use cases where veewee would be called by an automated process (e.g., Jenkins running a CI job) that may not be provided a traditional home directory (i.e., `/home/user`) and where its home location may be part of a path may be used by a service that has no business in knowing the values directly. The environment approach also provides the ability to have several definitions defined within a single automation server, and just varying the environmental configuration per job. For example, this could support building different environments or baselines during development.

I think it would be reasonable to check for `~/.fog` to use in configuring the service, effectively looking for that file if the environment variable is not set. Using `~/.fog` has the downside of having a configuration file that isn't explicitly associated with veewee, but this is perhaps a minor nit. I'm not completely convinced one way or another at this point. Near term, I will look at updating the current YAML structure to make the .fog file's parameter names to assist those that use both.