Working Directory to be set by a variable

[iskitsas]

It would be nice to be able all the output of our apps (crawler, doc-scanner, cli) to be written in a specific working directory under the user home folder.

For example:

Set the WORKING_DIR=~/.govdoc/ (this could be the default value if not set)
and when running the apps, a folder structure like this will be created

~/.govdoc/
        - crawler/
            - output
            - logs  
        - doc-scanner/
            - output
            - logs  
        - cli/
            - output
            - logs              

Check PR #33 for related work under env var OUTPUT_DIR