Singer 0.7.3.30

Add support injection of Pod Uid instead of hostname for text logger

How this feature works:
If prepend hostname is enabled for text logger config & singer is running in Kubernetes mode then attempt to use pod id as hostname if pod if is NOT null or NON_KUBERNETES_POD_ID else return hostname.

Singer 0.8.0-rc.1

logging-audit client implementation part 1:

1. Defined LoggingAuditHeaders which is used to uniquely identify each original message (event) and created singer-commons module which contains the AuditHeadersGenerator and thrift definition of LoggingAuditHeaders.

2. Implemented AuditableLogbackThriftLogger and AuditableLogbackThriftLoggerFactory which are able to inject LoggingAuditHeaders to LogMessage and to original thrift message.

3. Introduced HeadersProvider which is used to extract LoggingAuditHeaders from LogMessage and attach LoggingAuditHeaders to the headers of Kafka ProducerRecord.

4. Move com.pinterest.singer.metrics package and thrift files from thrift-logger module to singer-commons module.

Singer 0.7.3.29

1. fix some unit tests

2. add MissingDirChecker.java

Singer 0.7.3.28

Bug fixes:

1. Fix configuration type for DAILY_RESTART_TIME_END
2. replace OpenTsdbMetricsPusher with OpenTsdbStatsPusher

Singer 0.7.3.25

update singer with 0.7.3.25 changes (#3)