Enum AwsPropertyKeys inserted instead of Constants
Enum AwsPropertyKeys inserted instead of Constants
changeId: f82768d9da13ca236a9aac584144223b607b2adc
Constante has been replaced by Enum - it looks better

Conflicts:
	servo-aws/src/main/java/com/netflix/servo/tag/aws/AwsInjectableTag.java
Merge pull request #248 from eduardoraupp/master

Enum AwsPropertyKeys inserted instead of Constants