React svg xmlns:xlink identifier expected

Use the react specific spelling (JSX) for each attribute, for example:

return (
    <svg version="1.1" xmlns="http://www.w3.org/2000/svg" 
                   xmlnsXlink="http://www.w3.org/1999/xlink" >
         <defs> ... </defs>
         <use ... xlinkHref="#path-1"/>
    </svg>
);

• xmlnsXlink
• xlinkHref

also see:

• https://reactjs.org/blog/2016/04/07/react-v15.html