# Functions
NewFileSystemStore creates a Store backed by a file system directory.
NewMongoDBStore creates a new storage engine that uses MongoDB
The URL provided must point to a MongoDB server and database.
# Constants
MongoClaimsCollection is the name of the claims collection.
# Variables
ErrRecordDoesNotExist represents when file path is not found on file system.
# Interfaces
Store is a simplified interface to a key-blob store supporting CRUD operations.