Lowercase all fields when initially parsed?

[schuylermartin45]

While investigating some integration testing logs, I found that, on occasion, recipe files use capitalized field names, like Skip instead of skip.

This obviously breaks schema validation in rattler-build but presumably conda-build doesn't care.

We could easily correct for this BUT it does not appear this issue happens particularly often, so it is a lower priority issue.

[schuylermartin45]

Similarly, skip seems to get corrupted a lot of different ways. I see multiple skipt and skips in recipe files in Anaconda and Bioconda.

[schuylermartin45]

I only see one instance of this right now and that got solved with the "spelling corrections" change in this PR: #54

So I'm calling this closed for now.