"py -3" command does not work when pyenv is used.

[sosuts]

Hi! Thank you for the great package!
I have one question related to windows user.

If windows user installed Python with pyenv, I think Python would be launched by "python" command.
Therefore, "py -3" will cause an error in FD_HAS_PY3().
How about returning "python" when ENV["PYENV"] exists?

Franklin.jl/src/build.jl

Lines 1 to 11 in 5c8f5e1

	function PY()
	if "PYTHON3" ∈ keys(ENV)
	ENV["PYTHON3"]
	else
	if Sys.iswindows()
	"py -3"
	else
	"python3"
	end
	end
	end

[tlienart]

Hello!

Yes I think what you say makes sense. Maybe we could just add an if around line 6, would you be interested in a PR?

Note: the Python path in Franklin is bound to disappear. It is only used to run the minification (this script: https://github.com/tlienart/Franklin.jl/blob/master/src/scripts/minify.py relying on css_html_js_minify which is unmaintained and not great but simple); it's actually not particularly helpful so the next planned major release gets rid of Python, and of that dependency)

In short: if this is bothering you and you'd like to have a small fix for it for now, I'll gladly merge a PR to this effect, I was just commenting on the fact that in the medium term this will all go away 😄

[sosuts]

I apologize for the delayed response!
I sent a small PR 😉