Fix #70

-Use aggregation from titan with dataflow
-Add an aggregation-feedback topic
-Enable logging in UC2 with new slf4j version
-Use newer Kafkastreams version
-Remove unused ConfigurationKeys class

Because of suppress and a compute intensive log in the stream
application the use case may not produce any output.
Further a log message is added for every computed aggregation.

Use Titan CC Avro Records in UC App and Workload Generator

Closes #1, #10, #16, #18, and #34

See merge request !28

Add Distributed Workload Generator

Closes #18, #16, #10, and #28

See merge request !6

Clean up script names

Closes #37

See merge request !11

# Conflicts:
#   execution/uc1-workload-generator/deployment.yaml
#   execution/uc2-workload-generator/deployment.yaml
#   execution/uc3-workload-generator/deployment.yaml
#   execution/uc4-workload-generator/deployment.yaml

Resolve "Use Docker images from theodolite DockerHub organization"

Closes #55

See merge request !31

Resolve "Add deployment for Git tags"

Closes #57

See merge request !30

Resolve "Add equals/hash methods for serializable classes"

See merge request !29

As ints will not be null on a null check, better check for the values
of an int.

Send avro data with the producer to kafka.

Replace the kieker records with the avro records from titan.
Further use the builder pattern in the KafkaRecordSender to enable
creation with different parameters.

Abstract the Interface to be more generic.