API parameter "createTime" is now used by the join url.

API parameter createTime is now used, internally,  in join urls.

refs #722
This is not testing anything. I just removed this `createTime` and the one in the test below and it still works.
The point here is to make sure the user is being redirected to the string returned by `join_url`. Since you're defining what is returned by `join_url`, the value doesn't really matter. And it does not guarantee that `createTime` is being used.

You should add a new test to make sure `createTime` is included in the join url. Take a look at this test:

```ruby
context "gets a new config token before joining" do
  context "if the token is not nil" do
```

You can do something very similar.