Empire-client

Breaking changes:

- PyPi package is now called `empire`.

Documentation:

- Changed the help text

Fix:

- `empire.walkthrough` now demonstrates materialized views. (It
wasn't merged into 0.3.1)

Packaging:

- Improved packaging for PyPi

Breaking changes:

- PyPi package is now called `empire-client`. The module is still
called `empire`.

Features:

- `empire.walkthrough` now demonstrates materialized views.

Breaking changes:

- Materialized views are now manipulated through `materialize_view`,
`drop_view`, and `view_ready`

- Optional string parameter `enduser`, when creating an Empire
instance. This parameter is mandatory for performing materialized
view operations.

Dependencies:

- New dependency on `[python-dateutil](https://labix.org/python-dateutil)`

Features:

- `empire.view_materialized_at("viewname")` returns a `datetime`
object with the time the view was last materialized.

Features:

- `query` returns Python dicts

License:

- Changed to Apache License, Version 2.0