Inheriting from object was necessary for Python 2 compatibility to use
new-style classes. In Python 3, this is unnecessary as there are no
old-style classes.

Dropping the object is more idiomatic Python.

As numpy is Python 3 only, these import statements are now unnecessary
and don't alter runtime behavior.

This changes the behavior for:
* The `deg`  and `axis` arguments of `<type>der`
* The `deg`  and `axis` arguments of `<type>int`
* The `deg`  argument of `<type>gauss`
* The `deg`  argument of `<type>vander2d`
* The `deg`  argument of `<type>vander3d`

The old behavior was:
* Raise `ValueError` if the argument is a float, but not an integral one
* Allow a float like `1.0` to mean `1`.

This is inconsistent with most other integer-accepting APIs in numpy, which require these to be actual integers, and raise TypeError when they are not.

The new behavior is:
* Raise `TypeError` if the argument is a float, but not an integral one
* Emit a `DeprecationWarning` if a float like `1.0` is passed, continuing to allow it its old meaning.

That function is nose specific and has not worked since `__init__` files
were added to the tests directories.

The `lbnd` and `scl` parameters of the various polynomial integration
functions  are documented to be scalars. Add tests that those parameters
are checked and ValueError raised when it is not so.