Validate json files in new location
Validate json files in new location

We restructured the exercise files to live under exercises/:slug/*. This updates
the json linting script to look for the json files in their new location.

Fixes #371

exercism/x-common,Vankog/problem-specifications,jmluy/x-common,Vankog/problem-specifications,jmluy/x-common,ErikSchierboom/x-common,kgengler/x-common,rpottsoh/x-common,petertseng/x-common,rpottsoh/x-common,exercism/x-common,ErikSchierboom/x-common,jmluy/x-common,petertseng/x-common,kgengler/x-common