Added pip-python to the search for CentOS 6 compatibility

pip

@@ -136,6 +136,9 @@ def main():
         err += err_venv
 
     pip = module.get_bin_path('python-pip', False, ['%s/bin' % env])
+    if not pip:
+        pip = module.get_bin_path('pip-python', True, ['%s/bin' % env])
+
     if not pip:
         pip = module.get_bin_path('pip', True, ['%s/bin' % env])