bump version to 0.2.2
bump version to 0.2.2

songling88/zookeeper,songling88/zookeeper,songling88/zookeeper,zk-ruby/zookeeper,songling88/zookeeper,rickypai/zookeeper,rickypai/zookeeper,zk-ruby/zookeeper,zk-ruby/zookeeper,rickypai/zookeeper,rickypai/zookeeper