Update to latest linfa and plotters versions

[quietlychris]

Now that linfa 0.6 has been released, which does not require a BLAS dependency, it should be much easier for users to get started with using it. This book should be updated to the 0.6 release, and specify the 0.3.1 release of plottersfor generating plots.

[quietlychris]

Started in the linfa-0.6 branch

[quietlychris]

@bytesnake Unless you heavily object, I'm planning on removing the mdbook-scientific portion of this repository for the update relating to the 0.6 release. We're not currently using any of those features, and Bernard Schuster (the maintainer of Juice, a fork of the abandoned Autumn AI project Leaf) recently did a major refactor here and crates.io release of mdbook-scientific. If we want to use those features, I suggest that we can use that as a dep instead. Also, I think the MathJax support has significantly improved for mdbook anyway, so scientific notation is also accessible through that avenue.

[quietlychris]

Closed in #12