1. Open System Preferences => Keyboard => Shortcuts
2. Click on “Application Shortcuts”
3. Click the “+” to add a program
4. Under “Application:” click other
5. Navigate to Terminal (Applications/Utilities)
6. For the “Menu Title:” type “Show Next Tab” or “Show Previous Tab”
7. In “Keyboard Shortcut:” press the combo of keys you want (I used command+l and command+h for good integration with vim)
8. Click Add