This is what I get after running rake db:migrate:
vagrant@discourse:/vagrant$ rake db:migrateake db:migrate
== Seed from /vagrant/db/fixtures/001_categories.rb
Removing superflous categories columns!
rake aborted!
LoadError: Unable to autoload constant Version, expected /vagrant/lib/version.rb to define it
/home/vagrant/.rvm/gems/ruby-2.3.1/gems/seed-fu-2.3.6/lib/seed-fu/runner.rb:46:in `eval'
/home/vagrant/.rvm/gems/ruby-2.3.1/gems/bootsnap-1.0.0/lib/bootsnap/load_path_cache/core_ext/active_support.rb:53:in `block in load_missing_constant'
/home/vagrant/.rvm/gems/ruby-2.3.1/gems/bootsnap-1.0.0/lib/bootsnap/load_path_cache/core_ext/active_support.rb:6:in `with_bootsnap_fallback'
/home/vagrant/.rvm/gems/ruby-2.3.1/gems/bootsnap-1.0.0/lib/bootsnap/load_path_cache/core_ext/active_support.rb:53:in `load_missing_constant'
/home/vagrant/.rvm/gems/ruby-2.3.1/gems/activesupport-4.2.9/lib/active_support/dependencies.rb:184:in `const_missing'
/home/vagrant/.rvm/gems/ruby-2.3.1/gems/activesupport-4.2.9/lib/active_support/inflector/methods.rb:261:in `const_get'
/home/vagrant/.rvm/gems/ruby-2.3.1/gems/activesupport-4.2.9/lib/active_support/inflector/methods.rb:261:in `block in constantize'
/home/vagrant/.rvm/gems/ruby-2.3.1/gems/activesupport-4.2.9/lib/active_support/inflector/methods.rb:259:in `each'
/home/vagrant/.rvm/gems/ruby-2.3.1/gems/activesupport-4.2.9/lib/active_support/inflector/methods.rb:259:in `inject'
/home/vagrant/.rvm/gems/ruby-2.3.1/gems/activesupport-4.2.9/lib/active_support/inflector/methods.rb:259:in `constantize'
/home/vagrant/.rvm/gems/ruby-2.3.1/gems/activesupport-4.2.9/lib/active_support/core_ext/string/inflections.rb:66:in `constantize'
/vagrant/lib/discourse.rb:451:in `block in reset_active_record_cache'
/vagrant/lib/discourse.rb:450:in `each'
/vagrant/lib/discourse.rb:450:in `reset_active_record_cache'
/vagrant/lib/column_dropper.rb:42:in `drop'
(eval):29:in `block (2 levels) in run_file'
/home/vagrant/.rvm/gems/ruby-2.3.1/gems/seed-fu-2.3.6/lib/seed-fu/runner.rb:46:in `eval'
/home/vagrant/.rvm/gems/ruby-2.3.1/gems/seed-fu-2.3.6/lib/seed-fu/runner.rb:46:in `block (2 levels) in run_file'
/home/vagrant/.rvm/gems/ruby-2.3.1/gems/seed-fu-2.3.6/lib/seed-fu/runner.rb:58:in `block in open'
/home/vagrant/.rvm/gems/ruby-2.3.1/gems/seed-fu-2.3.6/lib/seed-fu/runner.rb:57:in `open'
/home/vagrant/.rvm/gems/ruby-2.3.1/gems/seed-fu-2.3.6/lib/seed-fu/runner.rb:57:in `open'
/home/vagrant/.rvm/gems/ruby-2.3.1/gems/seed-fu-2.3.6/lib/seed-fu/runner.rb:36:in `block in run_file'
/home/vagrant/.rvm/gems/ruby-2.3.1/gems/activerecord-4.2.9/lib/active_record/connection_adapters/abstract/database_statements.rb:213:in `block in transaction'
/home/vagrant/.rvm/gems/ruby-2.3.1/gems/activerecord-4.2.9/lib/active_record/connection_adapters/abstract/transaction.rb:184:in `within_new_transaction'
/home/vagrant/.rvm/gems/ruby-2.3.1/gems/activerecord-4.2.9/lib/active_record/connection_adapters/abstract/database_statements.rb:213:in `transaction'
/home/vagrant/.rvm/gems/ruby-2.3.1/gems/activerecord-4.2.9/lib/active_record/transactions.rb:220:in `transaction'
/home/vagrant/.rvm/gems/ruby-2.3.1/gems/seed-fu-2.3.6/lib/seed-fu/runner.rb:35:in `run_file'
/home/vagrant/.rvm/gems/ruby-2.3.1/gems/seed-fu-2.3.6/lib/seed-fu/runner.rb:26:in `block in run'
/home/vagrant/.rvm/gems/ruby-2.3.1/gems/seed-fu-2.3.6/lib/seed-fu/runner.rb:25:in `each'
/home/vagrant/.rvm/gems/ruby-2.3.1/gems/seed-fu-2.3.6/lib/seed-fu/runner.rb:25:in `run'
/home/vagrant/.rvm/gems/ruby-2.3.1/gems/seed-fu-2.3.6/lib/seed-fu.rb:29:in `seed'
/vagrant/lib/tasks/db.rake:20:in `block in <main>'
/home/vagrant/.rvm/gems/ruby-2.3.1/gems/rake-12.0.0/exe/rake:27:in `<top (required)>'
/home/vagrant/.rvm/gems/ruby-2.3.1/bin/ruby_executable_hooks:15:in `eval'
/home/vagrant/.rvm/gems/ruby-2.3.1/bin/ruby_executable_hooks:15:in `<main>'
Tasks: TOP => db:migrate
(See full trace by running task with --trace)
I also created admin user with bundle exec rake admin:create.