this is a pylint wrapper for Trove's tox tests. This commit includes a
basic infrastructure for running pylint through tox.
It also fixes some very obvious import errors that are flagged by the
tool. One is to handle missing imports for _ and _LE.
There is one instance where an exception is being raised but
trove.common.exception isn't imported, and another where an exception
is being incorrectly thrown.
A short readme is also provided.
Change-Id: I0a38f5efde3cb491f1f6c27f6c6500ab29987968
Partial-Bug: #1621636