Add renderInput property

[2manyvcos]

This would resolve #76

It adds a prop renderInput={(TagName, props) => InputNode}.

You could for instance use it to integrate it in Semantic UI React:

import { Input as SemanticInput } from 'semantic-ui-react'
...
import NumericInput from 'react-numeric-input'

const myNumberInput = (
  <NumericInput renderInput={(tagName, { ref, style, ...props }) => (
    <SemanticInput {...props} input={{ ref }} />
  )} />
)

[GuLinux]

any chance to have this merged in master? Looks good to me, and it would really help with semantic-ui-react integration