Print configuration values on bootup

[kenthklui]

Deimos has a number of default configurations, such as not using Avro encoding and decoding when run in development mode. Most of these configurations are implicit and not easily found without digging quite a bit into the code, but can cause cryptic errors when for example, an Avro encoded message is being consumed but not decoded with the correct decoder setting.

Printing configured settings on bootup would add some much needed clarity to avoid these problems.