#414 Add client module that configures a user client from the api impl

api/src/main/java/fitconnect/api/Subscriber.java

client/pom.xml

client/src/main/java/de/fitconnect/client/ClientBuilder.java

client/src/main/java/de/fitconnect/client/TestRunner.java

impl/pom.xml

impl/src/main/java/fitconnect/impl/SubmissionSender.java

.../src/main/java/fitconnect/impl/auth/FitCoAuthService.java

.../main/java/fitconnect/impl/crypto/FitCoCryptoService.java

.../java/fitconnect/impl/auth/OAuthTokenIntegrationTest.java

...est/java/fitconnect/impl/crypto/JWECryptoServiceTest.java

pom.xml