Fix build issue caused by pip error (10.0.1)

Change-Id: Ie36d8d5068c4a6dd3d2efc1c4adcb6ab723c4f06

Dockerfile

@@ -21,6 +21,7 @@ RUN apt-get update && apt-get install -y \
        python-dev \
        python-pip \
     && pip install -U -q pip \
+    && hash -r pip \
     && pip install -U -q setuptools \
     && cd /kloudbuster \
     && pip install -q -e . \

kb_dib/elements/kloudbuster/post-install.d/01-pip-package

@@ -1,4 +1,5 @@
 #!/bin/sh
 
 pip install --upgrade pip
+hash -r pip
 pip install setuptools wheel

kb_dib/elements/kloudbuster/post-install.d/99-cloudcfg-edit

@@ -5,7 +5,7 @@ cloudcfg = "/etc/cloud/cloud.cfg"
 user = "cloud-user"
 
 with open(cloudcfg) as f:
-  cfg = safe_yaml.load(f)
+  cfg = yaml.safe_load(f)
 
 try:
   if cfg['system_info']['default_user']['name']: