Add e2e tests for different types of documents

[jmartinm]

Basic e2e tests need to be added. Minimum to start can be:

• Open different types of records: literature, authors, conferences, ... and make sure the elements are on the page. Example different types of documents are available in https://github.com/inspirehep/inspire-schemas/tree/master/tests/integration/fixtures. They are missing $schema field. It needs to be added pointing to the appropriate schema (https://cernbox.cern.ch/index.php/s/Ouuokl6vlBfQXPf)
• Test that /holdingpen component works.