Added additional test verifying that andReturn expectation can accept and return NULL
Added additional test verifying that andReturn expectation can accept and return NULL

padraic/mockery,tfrommen/mockery,5outh/mockery,TiagoMaiaL/mockery,fhinkel/mockery,jenswiese/mockery,jenswiese/mockery,florianeckerstorfer/mockery,5outh/mockery,Big-Shark/mockery,yeka/mockery,Big-Shark/mockery,fhinkel/mockery,majisti/mockery,yeka/mockery,tfrommen/mockery,kminh/mockery,florianeckerstorfer/mockery,TiagoMaiaL/mockery,kminh/mockery