Bump to next development cycle

Signed-off-by: Jean-Yves Tinevez <tinevez@pasteur.fr>

Author: tinevez

pom.xml

@@ -10,7 +10,7 @@
 
 	<groupId>org.mastodon</groupId>
 	<artifactId>mastodon-tracking</artifactId>
-	<version>1.0.0-beta-20-SNAPSHOT</version>
+	<version>1.0.0-beta-21-SNAPSHOT</version>
 
 	<name>Mastodon Tracking</name>
 	<description>Basic tracking algorithms based on Mastodon data structures.</description>