update version 2.1.1 (#348)

Author: hujun-w-2

pom.xml

@@ -74,7 +74,7 @@
     </licenses>
 
     <properties>
-        <revision>2.1.1-RC</revision>
+        <revision>2.1.1</revision>
         <argLine>-Dfile.encoding=UTF-8</argLine>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>