Plugins break anaconda-project "README replacement" intention

[fpliger]

One of the main reasons for anaconda-project to exist is the need to reproducible project without having to do anything more than running anaconda-project run.

Plugins break this in the sense that we require users to install plugins before running anaconda-project run ... Ideally we need a way for anaconda-project to be "self-aware" of where/how to grab plugins.

A few potential scenarios can be:

• anaconda-project.yml defines the plugins it is using and anaconda-project installs them before running (not ideal since we change the main env where anaconda-project lives)
• anaconda-project let's users define the plugins deps in the command env itself and we somehow delegate the plugin resolution (and final execvp arg creation to the cmd env itself)
• having a pvt env isolated that acts as proxy for cmds and extensions..

\cc @bollwyvl @dsludwig @mmarchetti @havocp

[havocp]

#86 (bootstrap environments) was the solution we had in mind for this in the past.

[fpliger]

awesome! thanks @havocp