Craft 2.6.2999 install error: Base table or view already exists: 1050 Table 'craft_entryversions' already exists'
This is an indirect answer, but if you don't have time to debug the install process to set up a Vagrant box, grab this:

https://github.com/niceandserious/crafty-vagrant

Something about it doesn't trigger the duplicate table trouble. Someday I'll have time to figure out why.