Merge branch 'release/0.22.3'
Merge branch 'release/0.22.4'
Merge branch 'release/0.22.5'
Merge branch 'release/0.23.0'
Add joblib to RTD requirements file.
Merge branch 'release/0.23.1'
Fix typo in LICENSE.txt
Update year in LICENSE.txt
Merge branch 'release/0.24.0'

Conflicts:
	LICENSE.txt
Bump version to 0.25.0 and fix line-wrapping in documentation.
Merge pull request #123 from EducationalTestingService/release/0.25.0

Release 0.25.0
Add DOI to README
Merge branch 'hotfix/update_readme'
Merge branch 'master' into release/0.26.0

Conflicts:
	skll/version.py