ElementProperty improvements

[ardunn]

Summary

• Added ElementProperty preset for word embeddings of elements (add text-mined element embeddings to matminer via ElementProperty #343)
• Added quartile ability to property stats
• Update pymatgen requirement to newest pymatgen
• Update JMolNN --> JmolNN
• Assorted formatting

[computron]

Thanks! I am going to merge but then rename a bunch of things immediately afterward.

In the future, please don't mix multiple things (formatting changes, hot fixes, and a feature addition) in the same PR. In particular, the formatting changes are things that cause merge conflicts frequently, and it's best to separate those out into its own PR