update pom to use clojure.version property for CI and latest parent pom

Author: puredanger

pom.xml

@@ -17,7 +17,7 @@
   <parent>
     <groupId>org.clojure</groupId>
     <artifactId>pom.contrib</artifactId>
-    <version>0.2.2</version>
+    <version>1.0.0</version>
   </parent>
 
   <issueManagement>
@@ -41,11 +41,15 @@
     </developer>
   </developers>
 
+  <properties>
+    <clojure.version>1.5.1</clojure.version>
+  </properties>
+
   <dependencies>
     <dependency>
       <groupId>org.clojure</groupId>
       <artifactId>clojure</artifactId>
-      <version>1.5.1</version>
+      <version>${clojure.version}</version>
     </dependency>
     <dependency>
       <groupId>org.clojure</groupId>