added 'strictFunctionTypes: true' to tsconfig.json as recommended
added 'strictFunctionTypes: true' to tsconfig.json as recommended

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