Wiki-tools

* Reenable chempsider fetch
* Add cas_fetch and unii fetch
* Improve change_molecular to delete atom when zeroed

* Disable chempspider fetch and chempsider_fetch tests
* Improve README and refactor change_molecular for edge cases
* Add threads in WikiFinder for faster results

* Add pubchempy to increase speed for both WikiFiller and WikiFinder
* Remove selenium dependency for both WikiFiller and WikiFinder
* Fixed chebi fetch bug on multiple pages, now fetches first resul. Fixed other bugs
* Rewrite molecular_formula_fetch_nist; disable molecular_formula_fetch_wiki
* Add new_molecular_formula_fetch_nist and disable all tests for molecular_formula

* Small bugs fix
* Other names parsing increase
* Increase printing and fix chebi fetch
* Add tests for chebi fetch

* Categorie is new features added into WikiFiller
* Fix several bugs of imports and variable scope
* Add default drug categories and chemical categories
* Add GUI interface for choosing categories

* Fix a small bug and add small test in WikiFinder
* Add category and stub options for templates along with chemical and drug categories and stubs
* Add different categories to be used along with stubs