Update git submodules

* Update networking-generic-switch from branch 'master'
  to 58ee56cb948b63251213b6975fbd383b28c724d5
  - Use upper constraints in pep8 job

    use the same dependencies in both unit and lint tests,
    newer versions of dependencies may bring things like
    new flake8 extensions (example - neutron-lib).

    Change-Id: I324a74aa35620bb3a3549c0ee77b02c22c74dbcf
    Signed-off-by: Pavlo Shchelokovskyy <shchelokovskyy@gmail.com>

diff --git a/networking-generic-switch b/networking-generic-switch
index 55d0729c01df8eaab4ebeda466cd7fa3c2c758c4..58ee56cb948b63251213b6975fbd383b28c724d5 160000 (submodule)
--- a/networking-generic-switch
+++ b/networking-generic-switch
@@ -1 +1 @@
-Subproject commit 55d0729c01df8eaab4ebeda466cd7fa3c2c758c4
+Subproject commit 58ee56cb948b63251213b6975fbd383b28c724d5