Tests are currently unable to be run without extra options:

root@testvm-gss:~/foreman# RAILS_ENV=test bundle exec rake db:migrate
(in /root/foreman)
rake aborted!
Test::Unit or MiniTest must be loaded *before* Mocha (use MOCHA_OPTIONS=skip_integration if you know what you are doing).
/root/foreman/Rakefile:1:in `require'
(See full trace by running task with --trace)

root@testvm-gss:~/foreman# RAILS_ENV=test bundle exec rake test
(in /root/foreman)
rake aborted!
Test::Unit or MiniTest must be loaded *before* Mocha (use MOCHA_OPTIONS=skip_integration if you know what you are doing).
/root/foreman/Rakefile:1:in `require'
(See full trace by running task with --trace)

If you add the option specified, it seems ok (but no idea what other things it will break):

MOCHA_OPTIONS=skip_integration RAILS_ENV=test bundle exec rake test
[test results]