Issue #2281109: Porting 'Entity is of type (entity_is_of_type)' conditio...

...n to 8.x

See: d.o issue #2281109 - https://drupal.org/node/2281109
This creates an EntityIsOfType condition and an associated test that checks a simulated node's entity type.
Missing carriage return at end of file. Sorry.. Missed that the first time.