Fixed some tests

...tories/src/main/java/at/tuwien/mapper/MetadataMapper.java

...t/java/at/tuwien/endpoints/ContainerEndpointUnitTest.java

.../java/at/tuwien/endpoints/IdentifierEndpointUnitTest.java

...rc/test/java/at/tuwien/mapper/MetadataMapperUnitTest.java

.../test/java/at/tuwien/service/MetadataServiceUnitTest.java

...rvice/rest-service/src/test/resources/json/metadata0.json

...rvice/rest-service/src/test/resources/json/metadata1.json

...a-service/test/src/main/java/at/tuwien/test/BaseTest.java