Loading all SpaCy models slows down extraction

[loctimize]

When loading the SpaCy models, all models are loaded even if they are not used. See file spacy_models.py line 19 and following.
When adding more languages or using lg models, this might become a bottleneck and slow down the extraction process significantly.

Suggestion:
Check which language is requested and only load the required model, e.g. by changing from line 58 to (removing spacy_model = spacy_models[lang]):

        if lang == 'de':
            spacy_model = de_core_news_md.load()
        elif lang == 'en':
            spacy_model = en_core_web_md.load()
        ...

Then you would also be able to remove line 19-26.
What do you think?