Add note about being the last version to support 5.3
Add note about being the last version to support 5.3

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