Use additional sources for better coverage

• [x] http://unimorph.ethz.ch/languages
• [x] https://github.com/lenakmeth/Wikinflection-Corpus
• [x] https://github.com/TALP-UPC/FreeLing/tree/master/data/
• [x] https://github.com/explosion/spacy-lookups-data/tree/master/spacy_lookups_data/data
• [x] https://github.com/tatuylonen/wiktextract
• [ ] http://pauillac.inria.fr/~sagot/index.html#udlexicons

kaikki.org recently published a number of parsed dumps of Wiktionary in other languages. Could be interesting to include as they may have more morphology data.