Create Terminal does not activate pyenv environments

[DonJayamanne]

@brettcannon cc
Pyenv environments need to be activated like conda environments.
e.g.:
pyenv shell [name]

This was never done, is this required for the April release.

[brettcannon]

They don't need to be activated that way, it would just be nice and make @qubitron happy that he would get his global-install-with-Create Terminal scenario working. 😉