Bump version number. Minor bugfixes.

Author: Max Krogius

package.xml

@@ -2,7 +2,7 @@
 <?xml-model href="http://download.ros.org/schema/package_format2.xsd" schematypens="http://www.w3.org/2001/XMLSchema"?>
 <package format="2">
   <name>apriltag</name>
-  <version>3.1.1</version>
+  <version>3.1.2</version>
   <description>AprilTag detector library</description>
 
   <maintainer email="[email protected]">Max Krogius</maintainer>