Pinning version of flake8

Change-Id: Ib8a2b5e31383e200999d8f0d2f472e20d4c960bf
Signed-off-by: Mark Beierl <mark.beierl@canonical.com>
(cherry picked from commit eef2eb1c49dcf9cbac20a55471648cecbe01fecd)
2 files changed