TBR: lib/jenkins: remove token related code.
TBR: lib/jenkins: remove token related code.

As it turns out, we don't need token after all.
I will explain the reasons and how new Jenkins is set up in a doc.

Change-Id: Ic449ad178ea47b723b15a9305d994f4df19facea

vanadium/go.devtools,vanadium/go.devtools,vanadium/go.devtools