Added: database_type to configuration

[lizdeika]

Based on https://github.com/ClosureTree/closure_tree/pull/338

Adds ability to set database_type in initializers/closure_tree_config.rb:

ClosureTree.configure do |config|
  config.database_type = :mysql
end

The type will be used across all the closure tree models in the application.

This solves problems with numeric ordering and db:create.

[lizdeika]

Hi, Any possibility to have this released? Thank you

[seuros]

How we will handle this with activerecord 6 that support multiple database.?

[n-rodriguez]

IMHO this one is better https://github.com/ClosureTree/closure_tree/pull/338 since it's compatible with Rails 6 multi DB support.