Create reusable transaction generator for test apps

[litt3]

• Each test app has its own uniquely rolled setup to generate transactions at a certain rate
• A reusable utility object to perform this would be simple enough to create, and significantly decrease the complexity of existing and new test apps
• I think it makes sense to create a corresponding config class that can be reused, that allows the developer to configure the following aspects of transaction generation:
  • total rate
  • ramp up period