add default gitignore

Change-Id: I95f8e97e4a04dd157830f86ee27183331272a62f
switch/base.rb: refactor all model values

Change-Id: I1e190c7a95c1abf9acc725eee34ed1e8c1eecc06
refactor model lookup functions on model/switch.rb

Change-Id: I04f89c98672f72a7d22efb28c28fce243a819bee