Use the official get-pip.py location

Author: jaap3

manifests/installation.pp

@@ -3,7 +3,7 @@
   $python_version = $title,
 ) {
 
-  $get_pip_url = 'https://raw.githubusercontent.com/pypa/pip/1.5.6/contrib/get-pip.py'
+  $get_pip_url = 'https://bootstrap.pypa.io/get-pip.py'
 
   Exec {
     path    => ['/usr/bin', '/usr/local/bin', '/bin/'],