Pin pip to less than version 8 in install_puppet.sh

When we create a new server and install puppet, we also install pip.
That's awesome, except when pip >=8 breaks us. For now, pin it.

Change-Id: Id12f866f577c3ca2405a6049084c3cb0af82fde5

install_puppet.sh

@@ -214,7 +214,7 @@ function setup_pip {
         zypper --non-interactive in --force-resolution python python-xml
     fi
 
-    python get-pip.py
+    python get-pip.py -c <(echo 'pip<8')
     rm get-pip.py
     pip install -U setuptools
 }