Use "$HOME/.opspark" directory for user config

[harveysanders]

Typically when CLIs need to write some user specific configuration files, they're put in a directory in the user's $HOME directory.
For example, npm uses ~/.npm/, the AWS CLI tool uses a ~/.aws/.

We should use a ~/.opspark directory to place the user config files, auth and user.

It may be just here, but I'm sure how that is all used, so it will need a closer look

opspark/controller/github.js

Line 24 in 340e0ae

const applicationDirectory = `${env.home()}/opspark`;