numeric Select values are converted to a string

[Steve Chester]

Numeric values that are passed to <MenuItem are converted to a string in Formik.

Reproduction: https://codesandbox.io/s/nostalgic-artem-iw3hh0?file=/src/index.tsx

<Field name="age" component={Select}>
 <MenuItem value={10}>Age 10</MenuItem>
</Field>

In the above example, I would expect formik's age value to be typeof number but it is typeof string when selecting the menu item.