Added per-file metrics.
Fixing gemspec and tests.
Handle case where there was zero coverage data.
Bump version number.
Update Gemfile.lock to reflect simplecov-json version bump.
Merge remote-tracking branch 'schmutz/master' into schmutz

Conflicts:
	lib/simplecov-json.rb
	simplecov-json.gemspec
Merge pull request #4 from vicentllongo/schmutz

Merge schmutz/master