Added definition for options type. Removed MTLLoader.materials - there is only MaterialCreator.materials, judging from the source code.
Added definition for options type. Removed MTLLoader.materials - there is only MaterialCreator.materials, judging from the source code.

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