Merge pull request #78 from metacret/master

Create suro-file and suro-s3 module for less dependencies of suro-server
[Gradle Release Plugin] - pre tag commit:  '0.2.6'.
[Gradle Release Plugin] - new version commit:  '0.2.7-SNAPSHOT'.
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TestConnectionPool less flaky
Merge pull request #79 from metacret/iSSUE-65

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- PreDestroy : cancel pingTask
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Merge pull request #81 from thinker0/feature/cancelPingTask

- PreDestroy : cancel pingTask