fix(compliance): Added default for compliance; moved to lodash

* `deepmerge` replaced with `lodash`¹,
* `DEFAULT_CONFIG` created,
* changed dependency in `package.json`

Makes lamassu/lamassu-server#24 redundant.

Potentially BREAKING, since dependency change.

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¹ - Seems like the only difference between them is that `deepmerge` [reorders properties alphabetically](https://gist.github.com/chester1000/dd0609245d04a488bd51/revisions), and `lodash` maintains original order.