Add ruby 2.0 for travis-ci
Add ruby 2.0 for travis-ci

dannyfallon/dalli,akihiro17/dalli,leonid-shevtsov/dalli,uzzz/dalli,wjordan/dalli,jjb/dalli,indirect/dalli,mumoshu/dalli,nitinstp23/dalli,murtuzakz/dalli,dplummer/dalli,freeatnet/dalli,mperham/dalli,dtakahas/dalli,eagletmt/dalli,hirocaster/dalli,eileencodes/dalli,ScotterC/dalli,tlemburg/dalli,arthurnn/dalli,reverbnation/dalli,exact/dalli,retailnext/dalli,petergoldstein/dalli,vipulnsward/dalli,jaxi/dalli,godfat/dalli,petergoldstein/dalli,shaiguitar/dalli,mcka1n/dalli,mrb/dalli,linyows/dalli,jcxplorer/dalli,IFTTT/dalli