Catch Connection Error when redis isn't up #22

[0verbyte]

This handles the ConnectionError both when starting the server and if the redis server goes away during the request lifecycle.

[jparise]

I believe PEP8 style says no spaces around the =.

[jparise]

Thanks, this is helpful! Three small bits of feedback:

1. Could you include some unit tests that cover this change?
2. Are there other places this should be checked?
3. Would it be clearer to implement this check as a function decorator or context manager?

(I think the answer to (2) is "no" but wanted to make sure.)

[0verbyte]

1. Since travis handles the redis-server. What is the preferred way to handle the mock connections and simulate a failure bringing redis offline?
2. I don't believe any other routes should be checked at this time.
3. Has been converted to use a decorator. The decorator handles whether the connection is checked at server start or within a request.

[nichochar]

Nice, how about also printing a friendly error message? I'm debating if we need only a pretty error message like "Failed to connect to redis".
I don't mind using message + stacktrace, but let's make it user friendly.

[nichochar]

Awesome! Thanks for making the change @voidpirate

I also had some minor suggestions in the comments.

Please address before merge

• try calling the function in the try/except rather than the ping()

Won't block merge

• would be nice to have a custom error template
• tests

@jparise the reason I put the testing in the optional here is that I think we should actually mock the redis server entirely. I created an issue

[nichochar]

Minor nit: can we switch this to single quotes? I haven't done it yet, but I am going to write a coding style for this repo, and strings favor single quotes if possible.

[0verbyte]

I've made the changes. Thank you very much for the feedback :)

The fails on travis are actually not due to any of the code changes, but failed to install Python 3.5.

[nichochar]

Kicked the travis job back, and it's now successful.
Thanks for making all the changes @voidpirate !