[mlpack] mlpack 3.2.1 released

[Ryan Curtin]

Hello everyone,

I just released a bugfix version of mlpack: 3.2.1.  Here's a link to the
source:

  http://www.mlpack.org/files/mlpack-3.2.1.tar.gz

And here's the changelog:

  * Enforce CMake version check for ensmallen (#2032).

  * Fix CMake check for Armadillo version (#2029).

  * Better handling of when STB is not installed (#2033).

  * Fix Naive Bayes classifier computations in high dimensions (#2022).

Like every mlpack release, this was a big group effort.  Thank you to
everyone who contributed and made this a reality!

There are still a few goals remaining for our original 3.2.0 release
that will probably make it into a soon-to-be-released 3.2.2 version.
Here is the list of PRs for the milestone:

https://github.com/mlpack/mlpack/milestone/34

That list is by no means final or exclusive---if you see something that
you'd like to add to that list and are able to help us see it through,
we can definitely do that!

Anyway, if you have any issues with the release, please feel free to
open an issue on Github or ask for help on IRC or this mailing list.

Enjoy!

-- 
Ryan Curtin    | "Where we're going, we won't need eyes to see."
ryan at ratml.org |   - Dr. Weir