Class InteractiveQuery

Create a new interactive query to send to the client.  The name and
instructions are optional, but are generally displayed to the end
user.  A list of prompts may be included, or they may be added via
the `add_prompt` method.

:param str name: name of this query
:param str instructions:
    user instructions (usually short) about this query
:param str prompts: one or more authentication prompts

Overrides: object.__init__

Add a prompt to this query.  The prompt should be a (reasonably short)
string.  Multiple prompts can be added to the same query.

:param str prompt: the user prompt
:param bool echo:
    ``True`` (default) if the user's response should be echoed;
    ``False`` if not (for a password or similar)