MNT: Make fsl.scripts a native namespace package

fsl/scripts/__init__.py

-#!/usr/bin/env python
-#
-# __init__.py - The fsl.scripts package.
-#
-# Author: Paul McCarthy <pauldmccarthy@gmail.com>
-#
-"""The ``fsl.scripts`` package contains all of the executable scripts provided
-by ``fslpy``, and other python-based FSL packages.
-
-.. note:: The ``fsl.scripts`` namespace is a ``pkgutil``-style *namespace
-          package* - it can be used across different projects - see
-          https://packaging.python.org/guides/packaging-namespace-packages/ for
-          details.
-"""
-
-__path__ = __import__('pkgutil').extend_path(__path__, __name__)  # noqa