Issue #2950132 by mondrake, alexpott, tom_ek, Gábor Hojtsy, Pasqualle, andypost, Mile23, larowlan: Support PHPUnit 7 optionally in Drupal 8, while keeping support for ^6.5

Issue #2805993 by blazey, tom_ek, alexpott, Wim Leers, Lund, Virbius: Provide base class for actions that update a field on an entity