Part of #9744
Removes all redundant `# -*- coding: utf-8 -*-` lines from files, as python 3 automatically reads source code as utf-8 now.
`Signed-off-by: Jonathan de Jong <jonathan@automatia.nl>`
Python will return a tuple whether there are parentheses around the returned values or not.
I'm just sick of my editor complaining about this all over the place :)
Also:
- change the REST endpoint to have a "S" on the end (so it's now /read_markers)
- change the content of the m.read_up_to event to have the key "event_id" instead of "marker".