Change `adapters` to `profiles` for compatibility with simplecov 0.8

Simplecov renamed `adapters` to `profiles` in v0.8, and now gives a deprecation warning.  This PR fixes the deprecation and updates the dependency since it will fail with older versions of simplecov.

Arguably of course, this entire gem should now be renamed `simplecov-gem-profile`, but i'll leave that to you if you want.