feat(docparser): generate components based on jsonapi tags

[rlespinasse]

Purpose

The aim of this new feature is to begin the support of the jsonapi tags during the @openapi:schema component generation phase.

The specification format is available at http://jsonapi.org/format/

Overview

Currently, this pull request add support for the data, and includes top-level members of the root of every JSON API request and response containing data document. For a given Foo object, the use of jsonapi tags will generated all components needed to represent the jsonapi format of this object.

• Foo as a resource object
• FooAttributes
• FooCollection: as an array of resource objects
• FooData
• FooIdentifier: as a resource identifier object
• FooIdentifierCollection: as an array of resource identifier objects
• FooIdentifierData
• FooRelationships

Supported top-level members are

• data,
• includes (skippable with flag --without-jsonapi-includes).

The errors objects can be handle by json tags (with an ErrorObject and an ErrorsPayload components)

The meta, jsonapi, links top-level members of the document are not supported in this pull-request.

Others contents needed for the pull request

• Task make test will run dataset testing to validate the usage of the openapi-parser,
• Task make check will run dataset check to swagger convertion,
• Add support of string attribute in a json tag (see dataset/jsontags),
• Fix a typo in yaml tag of the server struct in docparser/model.go,
• Add specific utility methods to parse json, jsonapi, and validate separately,
• Field Items from Schema now support a single string value OR a array of Schema,
• All warnings during file parsing became fatal to the openapi file generation.

Others information

The content of this pull-request is currently used at my current work. And a first code review / pair programming on some parts have being done by @denouche (thanks to him)

Related to #18

[rlespinasse]

I move this PR in WIP because of included who need a flag to block the generation in the openapi file (needed to be supported by AWS API Gateway 😭)

[rlespinasse]

@alexjomin the PR is up-to-date

[rlespinasse]

@alexjomin @denouche the PR is up-to-date, I fix the conflict on the README.md file