Revert "Don't require micro_migrations in Rakefile"
Revert "Don't require micro_migrations in Rakefile"

Apparently it's needed to run tests

This reverts commit 17de12655d767c678c0fc56143f6db1ce7126d96.

travis-ci/travis-api,travis-ci/travis-api,Tiger66639/travis-api,travis-ci/travis-api,Tiger66639/travis-api