Build from OAS 6.3.0 (#312)

* Build from OAS 6.3.0

Merge pull request #292 from XeroAPI/OAS-6.2.0-xero-ruby

Build from OAS 6.2.0

Merge pull request #288 from XeroAPI/OAS-6.1.1-xero-ruby

Build from OAS 6.1.1

Merge pull request #287 from XeroAPI/xero-ruby-9.0.0

add ultimate subplans

Build from OAS 5.0.0 (#283)

Co-authored-by: manishT72x <manish.tanwar@xero.com>

Build from OAS 4.0.0 (#280)

* Build from OAS 4.0.0

* update rubocop gem

* fix broken links to xero developer guide

Merge pull request #276 from XeroAPI/xero-ruby-6.0.0

Build from OAS 3.0.3

Merge pull request #272 from XeroAPI/xero-ruby-5.0.0

Build from OpenAPI v2.39.0-v3.0.0

Merge pull request #262 from XeroAPI/xero-ruby-4.3.1

up rev json-jwt in gemspec

Merge pull request #261 from XeroAPI/xero-ruby-4.3.0

Xero ruby 4.3.0