release version 0.3.0 (#60)

MRG: fix `count` bug (#11)

* stop using _hash_murmur

* add test

* bump to v0.2.3

bump to version 0.2.2 (#8)

MRG: bad k-mer detection, forcing, and error handling (#7)

* rename lint

* handle errors a bit

* properly handle (and test) errors

* upd docs

* bump vers

* name ksize parameter in constructor

bump version