Updated git submodules

Project: releng/builder master b8d6c13f439fda647aeb7a0064e3862562513cd4

Merge "Install git-review using pip install in virtialenv"

Install git-review using pip install in virtialenv

The version of git-review supports --reviewers option which is not
available with the version of the package on centos7 repositories.

Updated the change to handle long workspace names with pip
modules instead of pip, inspired by global-jjb change #5093

Change-Id: I598350d6778760ea320a1128db46da0f80c711db
Signed-off-by: Anil Belur <abelur@linuxfoundation.org>

diff --git a/docs/submodules/releng/builder b/docs/submodules/releng/builder
index 57c9557ee88cb0224d81b45c193a03defdf81a06..b8d6c13f439fda647aeb7a0064e3862562513cd4 160000 (submodule)
--- a/docs/submodules/releng/builder
+++ b/docs/submodules/releng/builder
@@ -1 +1 @@
-Subproject commit 57c9557ee88cb0224d81b45c193a03defdf81a06
+Subproject commit b8d6c13f439fda647aeb7a0064e3862562513cd4