inputRef should support React.createRef odysseyscience#176

Author: mihaimartalogu

ReactS3Uploader.js

@@ -32,7 +32,10 @@ var ReactS3Uploader = createReactClass({
         server: PropTypes.string,
         scrubFilename: PropTypes.func,
         s3path: PropTypes.string,
-        inputRef: PropTypes.func,
+        inputRef: PropTypes.oneOfType([
+          PropTypes.object,
+          PropTypes.func
+        ]),
         autoUpload: PropTypes.bool
     },