Feature/YAML application properties files

[marcosstefani]

Examples:

# properties/application.yaml
version: 1.0
url: "pyyaml.test.com"

# properties/application-dev.yaml
integration:
  python:
    url: "http://teste"
    port: 8080
version: 2.0

yaml.property('version') ... output: 1.0 ... found: properties/application.yaml

yaml.property('version', 'dev') ... output: 2.0 ... found: properties/application-dev.yaml

yaml.property('integration.python.port', 'dev') ... output: 8080 ... found: properties/application-dev.yaml

yaml.property('url', 'dev') ... output: pyyaml.test.com ... not found: properties/application-dev.yaml ... found: properties/application.yaml

[marcosstefani]

Hi, why not apply this PR?