Update git submodules

* Update docs/submodules/snaps from branch 'master'
  - Merge "Restricting the magnum-pythonclient version to 2.1-2.2"
  - Restricting the magnum-pythonclient version to 2.1-2.2

    Using version >2.2 results in a runtime exception.

    Change-Id: I1c5d5c650004981f13a350d04c3ab359fc98799b
    Signed-off-by: spisarski <s.pisarski@cablelabs.com>

diff --git a/docs/submodules/snaps b/docs/submodules/snaps
index c5fd231..b690666 160000 (submodule)
--- a/docs/submodules/snaps
+++ b/docs/submodules/snaps
@@ -1 +1 @@
-Subproject commit c5fd2310c8e9f63cf607de7fa9c21f60ab877224
+Subproject commit b6906661c0c853761a4d65a5980e6f4f24194217