I just installed the AppDaemon Addon (V0.4.0) on Hass.io getting the exact same error.
No clue how to fix it, but I think the issue is the way the semver method parses the version information. it thinks that 0.81 is less than 0.77.0 because of the format of the version number.
EDIT: after doing some research and thinking a bout it some more, the semver function is throwing an error because the supervisor version is not in the proper semantic versioning format. the fix would be to either change the version format in hass.io or to change the appdaemon script to account for this.