* Move to preshed, obsoleting trustyc
* Switch __cinit__ to __init__, after discussion on cython-users
* Deprecate the hash-table module formerly named trustyc, in favour of new one named preshed.
* Move features and learner to thinc package, to be hosted on pip
* Move parser to use thinc package
* Upd setup
* Move tagger to thinc
* Move tagger features to their own file
* Begin refactoring tagger to use Beam class from thinc
* Progress on moving to generic beam and violation classes
* Tagger now using generic Beam and MaxViolation classes, and results seem correct.
* Remove unused import from tagger
* Whitespace
* Fix use of Address, to reflect new cymem version
* Upd requirements, for thinc