Fix issue 57

* Adjust end date for All day events as it comes back incorrectly from
the API.
* Handle support for events that span multiple days.
* Add tests & test data.
* Use moment-range to make it easier to check for dates within a range.
Merge pull request #61 from Rise-Vision/chore/issue-57

Fix issue 57
Multi-day events no longer show time
Merge pull request #62 from Rise-Vision/chore/issue-58

Multi-day events no longer show time
Update help link
Handle network error

Try requesting data again after 5 minutes, but don’t display an
on-screen error message.