This version includes as many of the less changes made in the Bootstrapbase theme from Moodle version 2.9 to Moodle version 3.0.
To support hardcoded Bootstrap2 grids in Moodle core I have added the old span[x] classes. These grids are used in the user preferences page and a new mustache templates.
If you are using bootstrap as a parent theme or just like to help please try Moodle 3.0 with theme and report any issues on the theme_bootstrap github issue list.