Add mocha adpater

spec/lib/mocha_adapter_spec.rb

@@ -0,0 +1,14 @@
+require 'rails_helper'
+
+describe MochaAdapter do
+  let(:adapter) { described_class.new }
+  let(:count) { 42 }
+  let(:failed) { 25 }
+  let(:stderr) { "#{count-failed} passing (20ms)\n\n#{failed} failing" }
+
+  describe '#parse_output' do
+    it 'returns the correct numbers' do
+      expect(adapter.parse_output(stderr: stderr)).to eq(count: count, failed: failed)
+    end
+  end
+end