Construct an Action on the connection.

The action is stored in conn.assigns.action for later access (configurable via the :key option).

Options

See Bodyguard.Action for descriptions of these fields.

• context - context module
• policy - policy module (defaults to context module)
• fallback - fallback function
• assigns - action assigns
• user – can be a 1-arity function (or {module, function_name}) that accepts the connection and returns the user
• key - the assign to set. Defaults to :action