Add tests for splits and bad video data

[pjbull]

#119 added a functionality to save out the splits if they weren't provided and to provided an all-zeros array with the correct shape if we can't load a video deep within the DataLoader. These items should have tests added for them:

• add test for splits files getting written out
• add test for bad video getting zeroes

[sunny1401]

@pjbull - Can I try working on this?

[ejm714]

@sunny1401 sure!

For the first one on having a splits.csv written out, take a look at the existing tests for other functionality having to do with splits in test_config.py: https://github.com/drivendataorg/zamba/blob/master/tests/test_config.py. You'll want to add a test case where splits get automatically assigned and then check that that csv gets written (per this line)

[papapizzachess]

I am a college student working on a software engineering project for the next weeks until the end of this year. This is my first open source project on Github. I would appreciate any information that might help.