Style open modal

src/components/Button.jsx

@@ -1,4 +1,5 @@
 import React from 'react'
+import classnames from 'classnames'
 import colors from '../config/colors'
 import { margins, fontSizes } from '../config/scales'
 
@@ -6,12 +7,13 @@ class Button extends React.Component {
   static propTypes = {
     onClick: React.PropTypes.func,
     style: React.PropTypes.object,
+    className: React.PropTypes.string,
   }
 
   render() {
     return <a
       onClick={this.props.onClick}
-      className="maputnik-button"
+      className={classnames("maputnik-button", this.props.className)}
       style={this.props.style}>
       {this.props.children}
     </a>