Normalize hash before parse the objects

[evgenii]

Hi guys. The example for building method is not working properly, it's build Document with nils

see example bellow or test case in branch:

[1] pry(main)>
[2] pry(main)>
[3] pry(main)> hash = {
[3] pry(main)*   data: [
[3] pry(main)*     {
[3] pry(main)*       id: 'a123',
[3] pry(main)*       type: 'user',
[3] pry(main)*       attributes: {
[3] pry(main)*         activated_at: '2020-06-11'
[3] pry(main)*       }
[3] pry(main)*     }
[3] pry(main)*   ]
[3] pry(main)* }
=> {:data=>[{:id=>"a123", :type=>"user", :attributes=>{:activated_at=>"2020-06-11"}}]}
[4] pry(main)> JSON::Api::Vanilla.build(hash)
=> #<JSON::Api::Vanilla::Document:0x00007f97e2adaaf8
 @container=#<Module:0x00007f97e2adae68>,
 @data=nil,
 @errors=nil,
 @keys={},
 @links={nil=>nil},
 @meta={nil=>nil},
 @objects={},
 @rel_links={},
 @superclass=#<Class:0x00007f97e2adadf0>>