Add @ConfigIgnore annotation for ignorable @ConfigProperties

[cpmoore]

I believe a @ConfigIgnore annotation should be added for fields that you don't want to be configured via @ConfigProperties

Currently if a class has an @ConfigProperties annotation it attempts to configure every variable in that class. This lead to an issue where I was trying to use @Inject to set a variable.
I was just using my configuration class as a single point of reference for that variable instead of having to inject it everywhere else.