Add Dataset#first! to Dataset::ACTION_METHODS
Add Dataset#first! to Dataset::ACTION_METHODS

This allows Model.first! to work.

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