## What changes were proposed in this pull request?

Fix instalation of mllib and ml sub components, and more eagerly cleanup cache files during test script & make-distribution.

## How was this patch tested?

Updated sanity test script to import mllib and ml sub-components.

Author: Holden Karau <holden@us.ibm.com>

Closes #16465 from holdenk/SPARK-19064-fix-pip-install-sub-components.

(cherry picked from commit 965c82d8)
Signed-off-by: Holden Karau <holden@us.ibm.com>

Minor since so few people use them, but it would probably be good to have a requirements file for our python release tools for easier setup (also version pinning).

cc JoshRosen who looked at the original JIRA.

Author: Holden Karau <holden@us.ibm.com>

Closes #10871 from holdenk/SPARK-10498-add-requirements-file-for-dev-python-tools.