PyEnv is smart enough to interpret PYENV_VERSION=1.2:3.4 as local versions 1.2 and 3.4. It would be nice if we could specify these; as well as specify multiple versions in .python-versions.

Currently I see only two small issues when trying to do the above:

1. The plugin attempts to install a version of python exactly matching PYENV_VERSION. To support multiple versions we'd have to split the value by ":".
2. The plugin reads .python-versions as is, so it ends up specifying multiple versions as line break separated "1.2\n3.4" which again fails for installation, as well as usage. Here we'd have to split by "line-break" and then join again by ":".