Fix tempest and plugins install by default

  * Disable .git folders drop

Change-Id: Iaff058bd0cdd40af77f2582afe794f3c9735c9f8
diff --git a/Dockerfile b/Dockerfile
index 2da265a..e928caa 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -7,7 +7,7 @@
     LANG=C.UTF-8 \
     LANGUAGE=$LANG \
     LOG_DIR='/root/tempest'
-SHELL ["/bin/bash", "-xec"]
+SHELL ["/bin/bash", "-o", "pipefail", "-xec"]
 USER root
 ADD data /var/lib/