created ability to load filepath for environments where app root access ...

...is not available for example /var/lib/env/.env

We are using amazon aws and our dev ops person is using a sym link for our node process and thus doesn't have access to the root of the app. This update lets the user select where the environment variables live. This also means that since I have two node apps that need the same .env file(staging server with dashboard app and game app) I can set a location for a single .env file and load it dry.