Merge branch 'simple-uc3' into firestore-test

.gitlab-ci.yml

helm/templates/kafka/kafka-cluster.yaml

helm/values.yaml

...rocks/theodolite/benchmarks/commons/beam/BeamService.java

.../buildSrc/src/main/groovy/theodolite.beam.dataflow.gradle

theodolite-benchmarks/settings.gradle

theodolite-benchmarks/uc1-beam-dataflow/.gitignore

theodolite-benchmarks/uc1-beam-dataflow/Dockerfile

theodolite-benchmarks/uc1-beam-dataflow/build.gradle

...odolite/benchmarks/uc1/beam/dataflow/Uc1BeamDataflow.java

...ks/theodolite/benchmarks/uc1/beam/flink/Uc1BeamFlink.java

...ks/theodolite/benchmarks/uc1/beam/samza/Uc1BeamSamza.java

...a/rocks/theodolite/benchmarks/uc1/beam/WriterAdapter.java

...ks/theodolite/benchmarks/uc2/beam/flink/Uc2BeamFlink.java

...ks/theodolite/benchmarks/uc2/beam/samza/Uc2BeamSamza.java

theodolite-benchmarks/uc3-beam-dataflow/.gitignore

theodolite-benchmarks/uc3-beam-dataflow/Dockerfile

theodolite-benchmarks/uc3-beam-dataflow/build.gradle

...odolite/benchmarks/uc3/beam/dataflow/Uc3BeamDataflow.java

...ks/theodolite/benchmarks/uc3/beam/samza/Uc3BeamSamza.java