building web-octave requires Jekyll 3.3

[Mike Miller]

Kai, all,

I just found out over a few minutes frustrations and searching that the
web-octave project requires Jekyll 3.3 or higher to build properly.

In particular, the "absolute_url" and "relative_url" Liquid filters are
new in Jekyll 3.3.

The latest Jekyll version in Debian is 3.1. Therefore it should at least
be mentioned somewhere that Jekyll should be installed with gem to get
the latest upstream version. Is it possible to put a minimum version
requirement in _config.yml so this could be caught automatically and
prevent someone from building and pushing a bad build?

Thanks,

-- 
mike