Update animal sniffer plugin to 1.20
diff --git a/pom.xml b/pom.xml
index 53becd8..d563aaa 100644
--- a/pom.xml
+++ b/pom.xml
@@ -143,7 +143,7 @@
       <plugin>
         <groupId>org.codehaus.mojo</groupId>
         <artifactId>animal-sniffer-maven-plugin</artifactId>
-        <version>1.19</version>
+        <version>1.20</version>
         <executions>
           <execution>
             <!-- This checks the source code of our project -->