Feature/consolitate apt commands

* Consolidated `apt-get` commands
* Updated `README.md` to include additional examples
* Created a Procfile for quickly creating/testing a linked environment. Usage notes in the file comments.
  
@ianks I know that calling `ENV DEBIAN_FRONTEND=noninteractive` in your `Dockerfile` can potentially cause persistence issues, but I didn't realize that setting it inline was a problem:

```
RUN apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install
```

Do you mind elaborating?