Add BioConda recipe

[LucoDevro]

Hi Erik,

Thanks a lot for developing this tool! Getting many KEGG records in a ready-to-use form this efficiently is an underestimated challenge.

I'm relying on kegg_pull as the KEGG API in my new gene cluster mining tool cfoldseeker. I'm about to release it on BioConda. kegg_pull was the only dependency not available on BioConda yet, so I made a BioConda recipe and submitted it for inclusion in BioConda.

kegg_pull is now also available from BioConda! With this PR, I'm attaching the BioConda recipe to the repo as well as adding installation instructions from BioConda in the README.

Unless you'd change its dependencies, there is no need to update the recipe manually at BioConda with every update of kegg_pull. BioConda's bot will do so with every update of your PyPi package. You'd only need to copy over the recipe here if you'd like to keep it up to date in kegg_pull's repo too. Let me know if you like to be added as recipe maintainer so you get notifications from BioConda as well and can submit manual recipe edits yourself.

[erikhuck]

Well done @LucoDevro ! And I'm pleased to know kegg_pull has been valuable for your project. I've left just a few comments on your pull request.

[LucoDevro]

Although I think it's technically possible to make Bioconda recipes dynamically resolvable, it goes against Bioconda's design of explicit dependencies (and is generally frowned upon).

Having the recipe in kegg_pull's repo is strictly not required, but personally I find it good practice that developers include an up-to-date recipe in their repos as well, as a back-up for the one hosted and processed by Bioconda.

So I see a few options for this PR:

1. You don't include the recipe in the repo. Then you don't have to update it here. That's fine. Nothing will break.
2. You include it in the repo, but manually update it with every new release of kegg_pull. In case of unchanged dependencies, you can just copy the one from Bioconda-recipes automatically generated by Bioconda-bot (it'll autobump the version number and the sha256). Otherwise, a manual override will be necessary.

I'm ok with maintaining the recipe in any case, it's not too much of a hassle. I'll get a notification anyway from the Bioconda bot when it spots a new PyPi release.