refactor(ngsi_v2.ContextBrokerClient)!: misleading log for does_entit…

…y_exist

BREAKING CHANGE: Renaming of `does_entity_exists` to `does_entity_exist`

For #167

CHANGELOG.md

@@ -1,5 +1,6 @@
-### v.0.2.4
+#### v.0.2.4
 - fixed ContextAttribute: wrong type conversion for value ([#173](https://github.com/RWTH-EBC/FiLiP/issues/173))
+- fixed Change does_entity_exists create error message if entity does not exist ([#167](https://github.com/RWTH-EBC/FiLiP/issues/167))
 
 #### v0.2.3
 - added `override_metadata` argument according to new metadata update semantics in orion (https://fiware-orion.readthedocs.io/en/master/user/metadata.html#updating-metadata) ([#157](https://github.com/RWTH-EBC/FiLiP/issues/157))