Fixed some tests

...src/main/java/at/tuwien/endpoints/IdentifierEndpoint.java

...t/java/at/tuwien/endpoint/IdentifierEndpointUnitTest.java

.../java/at/tuwien/endpoint/PersistenceEndpointUnitTest.java

.../at/tuwien/service/DataCiteIdentifierServiceUnitTest.java

...a/at/tuwien/service/IdentifierServiceIntegrationTest.java

...at/tuwien/exception/IdentifierUpdateBadFormException.java

...ices/src/main/java/at/tuwien/mapper/IdentifierMapper.java

...in/java/at/tuwien/service/impl/IdentifierServiceImpl.java

...tadata-db/test/src/main/java/at/tuwien/test/BaseTest.java

...a/at/tuwien/service/IdentifierServiceIntegrationTest.java

...ava/at/tuwien/service/MetadataServiceIntegrationTest.java

dbrepo-semantics-service/Dockerfile

dbrepo-semantics-service/app.py

dbrepo-semantics-service/test.sh