Move button to its own component

fix css linting errors

src/components/Button/Button.js

@@ -0,0 +1,23 @@
+import React, { PropTypes } from 'react';
+import withStyles from 'isomorphic-style-loader/lib/withStyles';
+import s from './Button.css';
+
+class Button extends React.Component {
+  static propTypes = {
+    children: PropTypes.node,
+    onClick: PropTypes.func,
+  };
+
+  handleClick = (event) => {
+    if (this.props.onClick) {
+      this.props.onClick(event);
+    }
+  };
+
+  render() {
+    const { children, ...props } = this.props;
+    return <button className={s.root} {...props} onClick={this.handleClick}>{children}</button>;
+  }
+}
+
+export default withStyles(s)(Button);