upgrades logback to 1.2.13 (only for tests)

Author: ivangsa

pom.xml

@@ -115,7 +115,7 @@
     <dependency>
       <groupId>ch.qos.logback</groupId>
       <artifactId>logback-classic</artifactId>
-      <version>1.2.11</version>
+      <version>1.2.13</version>
       <scope>test</scope>
     </dependency>
   </dependencies>