Update scale-generator version to 2.0.0
Update scale-generator version to 2.0.0

In accordance with https://github.com/exercism/problem-specifications/#major-version-changes:
renaming a property is a major version change.

petertseng/x-common,rpottsoh/x-common,jmluy/x-common,jmluy/x-common,exercism/x-common,ErikSchierboom/x-common,petertseng/x-common,jmluy/x-common,ErikSchierboom/x-common,rpottsoh/x-common,exercism/x-common