Error for project without Action Text

Reproduction steps:
1. Use a project without Action Text set up
2. Run `bundle exec rake mass_encryption:encrypt_all_in_tracks`

Expected:
3. No error

Actual:
3. Error output
```
ActiveRecord::StatementInvalid: PG::UndefinedTable: ERROR: relation "action_text_rich_texts" does not exist
LINE 9: WHERE a.attrelid = '"action_text_rich_texts"'::regclass
^
/Users/eriscott/development/mass_encryption/lib/mass_encryption/encryptor.rb:65:in `block in enqueue_track_encryption_jobs_for'
/Users/eriscott/development/mass_encryption/lib/mass_encryption/encryptor.rb:64:in `times'
/Users/eriscott/development/mass_encryption/lib/mass_encryption/encryptor.rb:64:in `each'
/Users/eriscott/development/mass_encryption/lib/mass_encryption/encryptor.rb:64:in `enqueue_track_encryption_jobs_for'
/Users/eriscott/development/mass_encryption/lib/mass_encryption/encryptor.rb:41:in `enqueue_encryption_jobs_for'
/Users/eriscott/development/mass_encryption/lib/mass_encryption/encryptor.rb:20:in `block in encrypt_all_later'
/Users/eriscott/development/mass_encryption/lib/mass_encryption/encryptor.rb:20:in `each'
/Users/eriscott/development/mass_encryption/lib/mass_encryption/encryptor.rb:20:in `encrypt_all_later'
/Users/eriscott/development/mass_encryption/lib/tasks/mass_encryption_tasks.rake:9:in `block (2 levels) in '
```

Workaround: name the class you want to use in encryption via the `ONLY="Klass"` parameter.