Change "robot" to "bot" in edit summaries

To avoid confusion of automated mechanical devices.
See https://www.mediawiki.org/wiki/Manual:Pywikibot/Development_guideline .

Whitespace changes to conform with PEP-8.

Change-Id: I72a39c62071b01d423c8e4a66e0691b47af4a48c
Follows-Up: Ic282107ba2af8a9c2af2b6bfb5c6fb25ed279038