Squashed 'tests/phpunit/includes/uninstall/' changes from 497e387..2caae35

2caae35 Correct two version numbers
d130be1 Document the $_blog_id class property
44cc35a Fix errors when running tests on a non-multisite install

git-subtree-dir: tests/phpunit/includes/uninstall
git-subtree-split: 2caae35147609ffc1ad7cf20d0506377384c6fa4
Merge commit 'da8dd62b76e73dc29257c02390c6faf9b68a8102'

Fixes failing build for non-multisite uninstall tests.