Adding temporary test buttons, to make sure that Heroku is running the most...

Adding temporary test buttons, to make sure that Heroku is running the most recent version of the App, so that deployment to Heroku is confirmed to work now

messages-app-frontend/src/App.tsx

@@ -158,7 +158,9 @@ export default class App extends React.Component{
           <Box sx={{textAlign: "center", paddingTop: 5}}>
             <Input value={this.state.newMessage} onChange={(p) => this.setState({newMessage: p.target.value})}></Input>
             <Button /*color="success"*/ sx={{margin: 1.5}} variant="contained" endIcon={<SendIcon />} onClick={this.createMessage}>Send</Button>
+            <Button variant='contained'>TEST BUTTON</Button>
           </Box>
+          <Button variant='contained'>TEST BUTTON</Button>
 
         </Container>