Add Ruby2.0.0 build in Travis-ci, and allowed to fail
Add Ruby2.0.0 build in Travis-ci, and allowed to fail

http://about.travis-ci.org/docs/user/build-configuration/#Rows-That-are-Allowed-To-Fail

awilkening/database_cleaner,simonmorley/database_cleaner,reinaris/database_cleaner,claptimes5/database_cleaner,avalonmediasystem/database_cleaner,yangc5/playlister-sinatra-v-000,yangc5/playlister-sinatra-v-000,yangc5/playlister-sinatra-v-000,glebtv/database_cleaner,yangc5/playlister-sinatra-v-000,yangc5/playlister-sinatra-v-000,eliotsykes/database_cleaner,amorphid/database_cleaner,yangc5/playlister-sinatra-v-000,HaiTo/database_cleaner,custora/database_cleaner,fajrif/database_cleaner,0xCCD/database_cleaner,DatabaseCleaner/database_cleaner,yangc5/playlister-sinatra-v-000,DatabaseCleaner/database_cleaner,ericraio/database_cleaner