fixed typo and tests

...in/java/dev/fitko/fitconnect/api/services/Subscriber.java

...fitconnect/api/services/validation/ValidationService.java

...in/java/dev/fitko/fitconnect/client/SubscriberClient.java

...va/dev/fitko/fitconnect/client/ClientIntegrationTest.java

...main/java/dev/fitko/fitconnect/core/SubmissionSender.java

.../java/dev/fitko/fitconnect/core/SubmissionSubscriber.java

.../fitconnect/core/validation/DefaultValidationService.java

.../java/dev/fitko/fitconnect/core/SubmissionSenderTest.java

...connect/core/validation/DefaultValidationServiceTest.java