Fix a bunch of layout issues

website/src/Dialog/MessageDialog.js

@@ -1,6 +1,6 @@
 import React from 'react'
 import PropTypes from 'prop-types'
-import { Modal, Button, Icon, StackLayout, Text } from '../ui'
+import { Modal, Button, Icon, Column, Text } from '../ui'
 
 export class MessageDialog extends React.Component {
   static propTypes = {
@@ -13,19 +13,19 @@ export class MessageDialog extends React.Component {
   render() {
     return (
       <Modal open={this.props.open} onClose={this.props.onDismiss} closeOnDimmerClick={false}>
-        <StackLayout>
-          <StackLayout.Item>
+        <Column>
+          <Column.Item>
             <Text>{this.props.title}</Text>
-          </StackLayout.Item>
-          <StackLayout.Item>
+          </Column.Item>
+          <Column.Item>
             <Text>{this.props.message}</Text>
-          </StackLayout.Item>
-          <StackLayout.Item>
+          </Column.Item>
+          <Column.Item>
             <Button onClick={this.props.onDismiss}>
               <Icon name='checkmark' /> OK
             </Button>
-          </StackLayout.Item>
-        </StackLayout>
+          </Column.Item>
+        </Column>
       </Modal>
     )
   }