Bug fixes

• Ensure elasticsearch reporting is enabled if onlyLogElasticsearchMetricReports is enabled. See #216. Thx @elFarto

New Configuration Features

What many of you might not know is that the configuration mechanism stagemonitor uses can also be used by other projects. The foundation is the ConfigurationOption builder which lets you build configuration options in a type safe manner. This release adds a bunch of new features.

• ConfigurationOptions can be marked as required
  • depending on ConfigurationOption.failOnMissingRequiredValues throw an IllegalStateException or warn if a required value is not available
• ChangeListeners can be attached to a ConfigurationOption to get notified about configuration changes
• Validators can be attached to ConfigurationOptions to validate the values
• If duplicate configuration keys are found, the Configuration constructor throws an IllegalArgumentException