PSR-4 autoloading standards

[dkjensen]

When loading this library via composer, the following errors are being presented when generating the autoloader

Class IMSGlobal\LTI\Deep_Link_Message_Validator located in ./vendor/imsglobal/lti-1p3-tool/src/lti/message_validators/deep_link_message_validator.php does not comply with psr-4 autoloading standard. Skipping.
Class IMSGlobal\LTI\Resource_Message_Validator located in ./vendor/imsglobal/lti-1p3-tool/src/lti/message_validators/resource_message_validator.php does not comply with psr-4 autoloading standard. Skipping.
Class IMSGlobal\LTI\Submission_Review_Message_Validator located in ./vendor/imsglobal/lti-1p3-tool/src/lti/message_validators/submission_review_message_validator.php does not comply with psr-4 autoloading standard. Skipping.

[pammel]

It doesn't inspire much confidence when IMSGlobal wants to define standards on the one hand, but doesn't adhere to standards itself (PSR-4).