PatternFly 3 version bumping

1. check out tag (e.g., v2.10.0)
2. in source/_config.yml, change the value of baseurl from '/' to tag value (e.g., '/2.10.0/')
3. run grunt build
4. copy the resulting source/_site/ folder to another location (like your desktop) and rename it to the corresponding tag value (e.g., 2.10.0)
5. check out master or create a dev branch based on master
6. in source/_config.yml, set baseurl back to '/'
7. copy renamed folder to source/
8. commit changes (should be the addition of the new folder and its contents)

Important: for this to work, all href and src attribute values contained within source/ must start with {{ site.baseurl }}.