Prepare for 1.15.2 release.

CHANGELOG.md

-# Changes in version 1.??.? - 2020-??-??
+# Changes in version 1.15.2 - 2020-05-17
+
+ * Medium changes
+   - Update to metrics-lib 2.13.0.
 
 
 # Changes in version 1.15.1 - 2020-04-30

build.xml

@@ -9,10 +9,10 @@
 
   <property name="javadoc-title" value="CollecTor API Documentation"/>
   <property name="implementation-title" value="CollecTor" />
-  <property name="release.version" value="1.15.1-dev" />
+  <property name="release.version" value="1.15.2" />
   <property name="project-main-class" value="org.torproject.metrics.collector.Main" />
   <property name="name" value="collector"/>
-  <property name="metricslibversion" value="2.12.2" />
+  <property name="metricslibversion" value="2.13.0" />
   <property name="jarincludes" value="collector.properties logback.xml" />
 
   <patternset id="runtime" >