Profile support

Test case:

Replicate the standard Spring Boot profile functionality. As described here: https://dzone.com/articles/spring-boot-profiles-1

Requirements:

• Given multiple properties files, application-${profle}.properties, select one as the active profile.
• The application.properties without profile serves as the master
• Override any key of the master in the specific profile

A couple of ideas:

• a functional configuration that can be applied in an override-able init method.
• a default profile argument, that can be set just as any other. This arg will be parsed before others to ensure that they can depend on the profile.