Allow file based configuration

[khakers]

Is your feature request related to a problem? Please describe.
A clear and concise description of what the problem is. Ex. I'm always frustrated when [...]
Issues such as shown in #78. Not everyone use docker, so allowing them to set configuration in different ways would improve the adaptability of use and simplify non containerized us cases.

Describe the solution you'd like
Allow users to configure through both environment variables (current, highest priority), a file (properties, json, other), and potentially other 12 factor methods. The configuration file path should be able to be specified via the command line in addition to wherever the default is.

Additionally, the current manner of configuration is hard to manage and inconsistent. It would be an improvement to migrate to a purpose built configuration library. Unfortunately, the choices for java are not nearly as good as those present in Go, so some research is required.