Start timestamp in simulators

Allow user configured start time for start of stream.

Support new DAS unit type

Added support for static data producer unit type.

Modularization support

Improve readability of code and extensibility in order to demonstrate a simple DAS producer that sends random values to the processing Kafka back-end.

1.0.4

Version 1.0.4

Updated Spring boot and Spring cloud version to the 2020.0.3 (Ilford release).
Updated Google Guava to latest version due to security concerns in the previous version used.