Merge pull request #827 from public/title-case

Standardise on sentence case for titles
cryptography.vectors
Load vectors from cryptography.vectors
Don't use the hazmat/vectors path anymore
Update test requirements
s/cryptography.vectors/cryptography_vectors/
Update release process
Update changelog
Simplify vector opener
Use with
License header
test the vector version matches
Import __about__
Update release docs more
Update tasks.py