Add optional permissions check for doc.py in generate_json_docs

[alexnitta]

Currently, the generate_json_docs method does not restrict which documentation is returned. Once issue #55 is closed, the new generate_raml_docs method will allow for restricting documentation on endpoints based on the 1) the user's context and 2) whether the endpoint requires permission.

Edit generate_json_docs so that it also allows for the same kind of controlled access.