Update git submodules

* Update docs/submodules/vswitchperf from branch 'master'
  - set version of matplotlib to 2.2.2 in requirments.txt.

    JIRA issues assoicated with the https://jira.opnfv.org/browse/VSPERF-591?filter=-1# VSPERF-591

    Extended description:
    Latest version of matplotlib 3.0.0 dosn't support python 3.4. Creating error during build.

    Change-Id: I05f14fb486a5b0090bf27c66de0d6e4c85652330
    Signed-off-by: Bob Fubel <bfubel@redhat.com>

diff --git a/docs/submodules/vswitchperf b/docs/submodules/vswitchperf
index 665dcb2..80b86f4 160000 (submodule)
--- a/docs/submodules/vswitchperf
+++ b/docs/submodules/vswitchperf
@@ -1 +1 @@
-Subproject commit 665dcb2b00632384762f2cf9754b2e2cdce6a69d
+Subproject commit 80b86f4e073dc6c9ca53704adc6b22c665e9f953