Add integration test for Model#lock!
Add integration test for Model#lock!

offshore-safety/sequel,nicohvi/sequel,freshpay/sequel,beni55/sequel,Marketcircle/sequel,seeARMS/sequel,dennis-d/custom_sequel,yazshel/sequel,tmm1/sequel,chef/sequel,nicohvi/sequel,freshpay/sequel,knut2/sequel,nju520/sequel,reubano/sequel,mpalmer/sequel,t-morgan/sequel,nju520/sequel,davidbegin/sequel,pfarrell/sequel,knut2/sequel,reubano/sequel,t-morgan/sequel,davidbegin/sequel,beni55/sequel,uhoh-itsmaciek/sequel,uhoh-itsmaciek/sequel,pfarrell/sequel,bigfix/sequel,gferguson-gd/sequel,offshore-safety/sequel,yazshel/sequel,offshore-safety/sequel,mpalmer/sequel,seeARMS/sequel,dennis-d/custom_sequel,gferguson-gd/sequel