Update git submodules

* Update docs/submodules/doctor from branch 'master'
  - Merge "ability to run maintenance test"
  - ability to run maintenance test

    JIRA: DOCTOR-119

    Change-Id: I98e556fba30eb7ba244cb9d0d88a9e95c39193ff
    Signed-off-by: Tomi Juvonen <tomi.juvonen@nokia.com>

diff --git a/docs/submodules/doctor b/docs/submodules/doctor
index e172646..776ad2a 160000 (submodule)
--- a/docs/submodules/doctor
+++ b/docs/submodules/doctor
@@ -1 +1 @@
-Subproject commit e172646a5957944bb232eee36bd7596e863b1b5a
+Subproject commit 776ad2a555b52a6d435f897a11217d669e88bca8