Update version of PyYAML

Change-Id: I9672c4cfc5e1aa3abcb67ee328fab299068c141c
Signed-off-by: Mark Beierl <mark.beierl@canonical.com>
(cherry picked from commit 79276b21b9c1b57a16cb3d000ae2c1dc055d3f46)
3 files changed