[maven-release-plugin] prepare release clojure-1.9.0-alpha2

Author: Hudson @ build.clojure.org

pom.xml

@@ -5,7 +5,7 @@
   <artifactId>clojure</artifactId>
   <name>clojure</name>
   <packaging>jar</packaging>
-  <version>1.9.0-master-SNAPSHOT</version>
+  <version>1.9.0-alpha2</version>
 
   <url>http://clojure.org/</url>
   <description>Clojure core environment and runtime library.</description>