making enh-ruby-op-face visible

### Before
notice things like :: and < on the class definition line 
![before](https://cloud.githubusercontent.com/assets/1127553/3565062/2a9d1f50-0aa6-11e4-8563-2634133412f4.png)

### After
![after](https://cloud.githubusercontent.com/assets/1127553/3565063/2c22dd10-0aa6-11e4-88a8-918a09f8cd96.png)