Handling conda labelled channels

:clipboard: **Description**

When a conda channel has labels, the latest_version doesn't need to match the last version in the versions list. I propose that there be a new badge for conda like:

https://img.shields.io/conda/vln/:channel/:package.svg

channel | v0.4.0a0


:link: **Data**

Same public Anaconda Cloud API that is already used for the other conda badges:
https://api.anaconda.org/package/{channel}/{package}
example: https://api.anaconda.org/package/pyviz/panel

The part to use would be the last item in versions: `package.versions[package.versions.length - 1];`

:microphone: **Motivation**

I am building a [status dashboard](http://status.pyviz.org) for the [pyviz project](http://pyviz.org) and we publish dev releases to pyviz/label/dev.

Start by locating the existing conda badge implementation and comparing its Anaconda Cloud API handling with the package/{channel}/{package} response described here. Add the labelled-channel version badge using the last item in package.versions, and verify the output matches the provided channel | v0.4.0a0 example.

Written by the indexing model from the issue text.