dhellmann ignore warning from bandit for using shell=
The functions in this library are meant to wrap subprocess, and
sometimes we do want to allow passing shell=True, so mark that line
with nosec to ignore B604.

Change-Id: Iab676449e543a4fdabee62efa9283940d30e3398
Signed-off-by: Doug Hellmann <doug@doughellmann.com>
Latest commit 9a4dea3 Aug 16, 2018