Fix pip version install

Install fixed pip version 9.0.3

Change-Id: Ibabc187ac58cd6c05ec99ef8ebfd407538500fd0
diff --git a/Dockerfile b/Dockerfile
index 6a22a44..81fb489 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -32,7 +32,7 @@
   && apt-get update && apt-get  upgrade -y \
   && apt-get install -y vim-tiny git-core python-pip libffi-dev libssl-dev python-dev python3-dev iputils-ping patch
 
-RUN pip install -U pip
+RUN pip install -U 'pip==9.0.3'
 WORKDIR /var/lib/
 # TODO migrate to downstrem mirror?
 RUN git clone https://github.com/openstack/requirements.git openstack_requirements && \