fix: introduced forwardRef (#185)

src/muiComponents/DialogContent/DialogContent.tsx

@@ -0,0 +1,10 @@
+import React, { forwardRef } from 'react';
+import { default as MaterialUIDialogContent, DialogContentProps } from '@material-ui/core/DialogContent';
+
+type DialogContentRef = HTMLDivElement;
+
+const DialogContent = forwardRef<DialogContentRef, DialogContentProps>(function DialogContent(props, ref) {
+  return <MaterialUIDialogContent {...props} ref={ref} />;
+});
+
+export default DialogContent;

src/muiComponents/DialogContent/index.ts

@@ -0,0 +1 @@
+export { default } from './DialogContent';