revert typescript version bump
revert typescript version bump

georgemarshall/DefinitelyTyped,magny/DefinitelyTyped,borisyankov/DefinitelyTyped,georgemarshall/DefinitelyTyped,markogresak/DefinitelyTyped,georgemarshall/DefinitelyTyped,georgemarshall/DefinitelyTyped,borisyankov/DefinitelyTyped,mcliment/DefinitelyTyped,magny/DefinitelyTyped,dsebastien/DefinitelyTyped,dsebastien/DefinitelyTyped