Switch Travis configuration
Switch Travis configuration

Start testing on ruby 2.0, drop support for testing jruby-head,
ruby-head, and ree, remove allowed failures.

Marketcircle/sequel,reubano/sequel,pfarrell/sequel,reubano/sequel,bigfix/sequel,gferguson-gd/sequel,gferguson-gd/sequel,mpalmer/sequel,beni55/sequel,dennis-d/custom_sequel,freshpay/sequel,freshpay/sequel,seeARMS/sequel,nicohvi/sequel,t-morgan/sequel,knut2/sequel,davidbegin/sequel,beni55/sequel,knut2/sequel,mpalmer/sequel,seeARMS/sequel,chef/sequel,davidbegin/sequel,nju520/sequel,offshore-safety/sequel,offshore-safety/sequel,uhoh-itsmaciek/sequel,yazshel/sequel,nicohvi/sequel,pfarrell/sequel,yazshel/sequel,offshore-safety/sequel,t-morgan/sequel,nju520/sequel,dennis-d/custom_sequel,uhoh-itsmaciek/sequel