Fix: status 500 error displayed in the console when adding new entry

[laylar]

There is still a status 500 error displayed in the console, perhaps the app is making multiple POST requests, or maybe there's something wrong in the redux actions for addEntry. Hmm....

Originally posted by @laylar in laylar/clevername-react#17 (comment)

[laylar]

It seems to be this .catch in ActionCreators.js:

.catch((error) => {
  console.log("post entry", error.message);
  alert("Your entry could not be posted\nError: " + error.message);
});

still, not sure why it's getting all the way to .catch even though it submitted properly. Huh.