[FEATURE] Generator moved from development to runtime environment.

Generators::Generate moved to ActiveRecordInstall::Generate. Now it is possible to
use it as a part of another generator:

    require 'active_record_install'
    class MyGenerator < Thor::Group

      def add_install_generator
        in_root { ActiveRecordInstall::Generate.start }
      end
    end

== Changes

* Generators::Generate -> ActiveRecordInstall::Generate

== Version

Release 0.1.0 launched for the new feature being added.