Bump version number (to 2.1.1?)

[luizirber]

Currently the bioconda recipe is failing due to changes in the rand crate:
https://github.com/bioconda/bioconda-recipes/blob/80f482466ec39833454d745c4f2e437de0bf6120/build-fail-blacklist#L35

But the master branch works fine, so maybe tag it as 2.1.1?

[johanneskoester]

Thanks for the heads up. We will do a new release soon.

[johanneskoester]

We have that release now, which is actually the final one, since prosic is now varlociraptor.

[dlaehnemann]

@johanneskoester has just released a new version and there is an attempt at unblacklisting:
bioconda/bioconda-recipes#17807