Turtle code implementation when generating html multi page does not work

[bejar]

When generating html multi page, the generation of the turtle code implementation fails with the
error "Error: Pygmentize Failed".

I have had a look at the code and in the file core/viz_factory.py in line 235, the method "serialize"
is called for an object of type OntoProperty. Its superclass RDF_entity has a method "rdf_source" that
by default returns the turtle representation of the object. I have patched the code so this method
is called instead and this fixes the problem.

[VladimirAlexiev]

About #12: turns out I already have it

>pip install pygments
Requirement already satisfied: pygments in c:\users\vladimir.alexiev\appdata\local\programs\python\python35\lib\site-pac
kages (2.2.0)

@lambdamusic could you make a release with @bejar's fix?

Cheers!

[lambdamusic]

Thanks for the feedback. I've updated the library Ontodocs relies on, which is what caused the error (@bejar well spotted!)

Now fixed: lambdamusic/Ontodocs#18

The new version is available on Pypi