* Fix on_match callback and remove empty patterns (#6312)
For the `DependencyMatcher`:
* Fix on_match callback so that it is called once per matched pattern
* Fix results so that patterns with empty match lists are not returned
* Add --prefer-binary for python 3.5
* Add version pins for pyrsistent
* Use backwards-compatible super()
* Try to fix tests on Travis (2.7)
* Fix naming conflict and formatting
* Update pkuseg version in Chinese tokenizer warnings
* Some changes for Armenian (#5616)
* Fixing numericals
* We need a Armenian question sign to make the sentence a question
* Update lex_attrs.py (#5608)
* Fix compat
* Update Armenian from v2.3.x
Co-authored-by: Ines Montani <ines@ines.io>
Co-authored-by: Karen Hambardzumyan <mahnerak@gmail.com>
Co-authored-by: Marat M. Yavrumyan <myavrum@ysu.am>
* Implement new API for {Phrase}Matcher.add (backwards-compatible)
* Update docs
* Also update DependencyMatcher.add
* Update internals
* Rewrite tests to use new API
* Add basic check for common mistake
Raise error with suggestion if user likely passed in a pattern instead of a list of patterns
* Fix typo [ci skip]
<!--- Provide a general summary of your changes in the title. -->
## Description
* tidy up and adjust Cython code to code style
* improve docstrings and make calling `help()` nicer
* add URLs to new docs pages to docstrings wherever possible, mostly to user-facing objects
* fix various typos and inconsistencies in docs
### Types of change
enhancement, docs
## Checklist
<!--- Before you submit the PR, go over this checklist and make sure you can
tick off all the boxes. [] -> [x] -->
- [x] I have submitted the spaCy Contributor Agreement.
- [x] I ran the tests, and all new and existing tests passed.
- [x] My changes don't require a change to the documentation, or if they do, I've added all required information.
