Merge branch 'feature/147-add-beam-implementations' into 'master'

.gitlab-ci.yml

theodolite-benchmarks/beam-commons/build.gradle

...ain/java/theodolite/commons/beam/AbstractBeamService.java

...c/main/java/theodolite/commons/beam/AbstractPipeline.java

.../main/java/theodolite/commons/beam/ConfigurationKeys.java

...n/java/theodolite/commons/beam/kafka/EventTimePolicy.java

...lite/commons/beam/kafka/KafkaActivePowerRecordReader.java

...e/commons/beam/kafka/KafkaActivePowerTimestampReader.java

...ava/theodolite/commons/beam/kafka/KafkaGenericReader.java

...odolite/commons/beam/kafka/KafkaWriterTransformation.java

...rks/buildSrc/src/main/groovy/theodolite.beam.flink.gradle

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

...rks/buildSrc/src/main/groovy/theodolite.beam.samza.gradle

...-benchmarks/docker-test/uc1-beam-flink/docker-compose.yml

...-benchmarks/docker-test/uc1-beam-samza/docker-compose.yml

...-benchmarks/docker-test/uc2-beam-flink/docker-compose.yml

...-benchmarks/docker-test/uc2-beam-samza/docker-compose.yml

...-benchmarks/docker-test/uc3-beam-flink/docker-compose.yml

...-benchmarks/docker-test/uc3-beam-samza/docker-compose.yml

...-benchmarks/docker-test/uc4-beam-flink/docker-compose.yml