text: Title: Keeping binder-env synced when we make a new release
  Body: Our binder examples use a docker image built from [this environment](https://github.com/ploomber/binder-env), however, whenever we release a new ploomber version, we want to re-built the environment, to always serve examples with the most recent version. 
  
  Currently, we're doing it manually but it'd be great to automate it. For example, [conda-forge](https://github.com/conda-forge/ploomber-feedstock/pull/13) has a bot that opens a PR whenever it detects a new Ploomber version.
  
  Any ideas on how to do this is appreciated!