refactor/session_aware

- remove mk1 clock timer (move to mk1 plugin)
- remove skill_api methods
- make session aware (timezone, time_format, date_format)
- use datetime utils from ovos-utils, dont make UTC assumptions (or at least let all tz assumptions be made in that module)

requirements.txt

@@ -3,4 +3,4 @@ tzlocal>=1.3
 timezonefinder~=5.2
 geocoder~=1.38
 ovos-utils~=0.0, >=0.0.38
-ovos_workshop~=0.0, >=0.0.15
+ovos_workshop~=0.0, >=0.0.16a25