Fixes a bug for single table inheritence

[aq]

Those lines replaced all the attributes of a record during a soft destroy:

• https://github.com/JackDanger/permanent_records/blob/b681ccf1ec2bc12e5004d14e792e3b193a08acb7/lib/permanent_records.rb#L87
• https://github.com/JackDanger/permanent_records/blob/b681ccf1ec2bc12e5004d14e792e3b193a08acb7/lib/permanent_records.rb#L78
• https://github.com/JackDanger/permanent_records/blob/b681ccf1ec2bc12e5004d14e792e3b193a08acb7/lib/permanent_records.rb#L99 Example:

class Branche < ActiveRecord::Base
  include ActiveRecord::SoftDestroyable
  has_many :sub_branches, foreign_key: 'parent_id', class_name: 'Branche'
  belongs_to :main_branche, foreign_key: 'parent_id', class_name: 'Branche'
end
main_branche = Branche.create
main_branche.id # => 1
sub_branche = Branche.create parent_id: main_branche.id
sub_branche.id # => 2
sub_branche.destroy!
sub_branche.id # => ! 1 in place of 2
 # because the instance attributes have been replaced.

The spec was a false positive because the relation between hole and location is has_one not has_many:

• https://github.com/JackDanger/permanent_records/blob/b681ccf1ec2bc12e5004d14e792e3b193a08acb7/spec/permanent_records/circular_sti_dependency_spec.rb#L6-L8
• https://github.com/JackDanger/permanent_records/blob/b681ccf1ec2bc12e5004d14e792e3b193a08acb7/spec/support/hole.rb#L12

[JackDanger]

Awesome work! Merging!

[JackDanger]

I've pushed gem version 4.1.5 with your changes and added your Github username as an author. Thanks, @aq !