"By the Code of Civil Procedure of New York in force prior to September 1, 1877, the period of six years was prescribed as the limitation for '(1) an action upon a contract, obligation, or liability, express or implied, except a judgment or sealed instrument; * * * (6) an action for relief, on the ground of fraud, in cases which heretofore were solely cognizable by the court of chancery,??the cause" . . . . .