Fix lint error

Author: veronicaguo

pvlib/pvsystem.py

@@ -1800,7 +1800,8 @@ def retrieve_sam(name=None, path=None):
 
     Notes
     -----
-    Files available at https://github.com/NREL/SAM/tree/develop/deploy/libraries
+    Files available at
+        https://github.com/NREL/SAM/tree/develop/deploy/libraries
     Documentation for module and inverter data sets:
         https://sam.nrel.gov/photovoltaic/pv-sub-page-2.html