Fix bug with string validation

Fix error with string validation, when input is not a string (eLama/php-raml-parser#30)

Inheritance support for union types & dates item type for array type

• Added inheritance support for union types
• Added dates item type for array type
• Fix union type parsing in libraries
• Fix composition of error message when Type fails validation
• Drop PHP 5.5 support

Support for `Resource` prefixes, `Resource` being parent-aware

• Support for resource prefixes (by @arheyy)
• Make subresource aware of its parent (by @vbartusevicius)
• Add helper method for removing resource from the ApiDefinition
• Fix class name (DateTimeType -> DatetimeType)
• Fix time format in TimeOnlyType to H:i:s
• Improve CI with reacher matrices and less pointless repeating checks

Better Traits and SecurityScheme support

New features (thanks to @vbartusevicius)

• Support for Trait inheritance
• Traits are parsed same way as Types
• Improvements to SecurityScheme parsing with support for RAML 1.0

Other changes

• Unified code style across the whole repository
• Improvements to Travis

Change of the composer project name to "raml-org/raml-php-parser"

4.0.0

Update package name in composer.json

Bugfix release

• Allow requests with an empty body (#114, thanks to @jefferson-lima)
• Propagates Resource uriParams definition to all its subresources (#102, thanks to @thesebas)

RAML 1.0 Support

This release is based on backported changes from @Elama 's fork.
It comes with support for RAML 1.0 and updated dependencies.

Support for Symfony 4 components and route protocol override

• Allow Symfony 4 components in the dependency list
• Provide support for method that overrides the API protocol values (by @RETFU)
• Test modern PHP versions in CI

RequestValidator, ResponseValidator and support for Symfony 3

#104 Support for Symfony 3 by @kubawerlos
#105 Added RequestValidator and ResponseValidator by @pies

The library requires PHP 5.5.9 now and composer.lock was removed.