How to install oauth2client?
oauth2client is available in the official Kodi repository which is included by default in Kodi. You can install this addon by going in Kodi to System >> Settings >> Addons >> Get Addons >> XBMC.org Addons or Kodi.tv Addons
About SuperRepo and oauth2client
SuperRepo does not maintain oauth2client. We only provide an automated index for Kodi users to have easy access to oauth2client and other addons for Kodi. We are not affiliated with the developers (Google) and do not provide help for this particular addon.