adding grpcio-tools to basebuild

Change-Id: I554d9746660f42b15a0b0fef15ca60f80b6b8a5f
diff --git a/packer/provision/basebuild.sh b/packer/provision/basebuild.sh
index d5a809a..cfee70e 100644
--- a/packer/provision/basebuild.sh
+++ b/packer/provision/basebuild.sh
@@ -85,6 +85,7 @@
         docker==3.2.1 \
         gitpython \
         graphviz \
+        grpcio-tools \
         isort \
         linkchecker \
         pexpect \