“An Act to revise the law in relation to arbitrations and awards”, approved June 11, 1917, as amended, is repealed; provided, however, that any agreement entered into prior to the effective date of this Act to submit to arbitration a dispute existing at the date of the agreement shall be governed by said Act approved June 11, 1917; provided further, that this Act does not impair the validity of any proceeding under said Act, approved June 11, 1917, commenced prior to the effective date of this Act.