Throw exception if calculation time is out of range

[Deuchnord]

Add support for the OutOfRangeError exception thrown by JplEphem in brandon-rhodes/python-jplephem#36.

Basically, we catch the raised exception on JplEphem's side and re-throw a Skyfield-specific one with the times converted in Time objects.

Fix #319

[brandon-rhodes]

Thanks, hopefully I'll have a chance to take a look later this week!

[brandon-rhodes]

This looks good, thanks for doing this work!

1. I've asked for a small code change.
2. And also an API/feature tweak.
3. Also: could you add a unit test for the feature? You'll want to create a new file test_jpllib.py since it's a test specific to this suite.

Thanks, I look forward to merging this!

[Deuchnord]

Hi @brandon-rhodes, sorry for the late, didn't have much time this week to fix the review.

Also: could you add a unit test for the feature? You'll want to create a new file test_jpllib.py since it's a test specific to this suite.

I'm not sure how I should proceed for that… at first sight, looks like I should mock the JplLib library, but I don't know the tests framework you're using… do you have any doc for it?

[brandon-rhodes]

Thanks for contributing this! The feature should appear in the next release of Skyfield.