refactor/db-calls: reduce DB usage

[rudyardrichter]

Resolves #66.

Notable changes:

• Removes the original get_current_user() usage; instead, uses current_user proxy which will do at most 1 lookup for user per request and store the user info from the database as a dictionary
• Changes endpoints to use require_auth (instead of login_required) and use the current_token proxy where possible to get necessary information from the token instead of database
• Changes MOCK_AUTH to be an entire fake token instead of a boolean, to support "stateless" mocked auth

Changes left:

• Change storage manager setup to use token (place that only needs username)
• Appease codacy