Register when the config files were last updated

src/main/resources/advanced.yml

@@ -1,5 +1,6 @@
 #
 #  Advanced configuration
+#  Last updated on ${project.version}-b${BUILD_NUMBER}
 #
 #  For advanced users only! There is no need to change anything here.
 #

src/main/resources/child.yml

@@ -1,5 +1,7 @@
 #
 #  mcMMO child skill configuration
+#  Last updated on ${project.version}-b${BUILD_NUMBER}
+#
 #  You do not need to modify this file except to change parents of child skills
 #
 #  If you wish a child skill to be the parent of another child skill, you must also make your changes to the child.yml within the jar

src/main/resources/experience.yml

@@ -1,5 +1,6 @@
 #
 #  Experience configuration
+#  Last updated on ${project.version}-b${BUILD_NUMBER}
 #
 #  Configure the experience formula and experience settings here.
 #

src/main/resources/treasures.yml

@@ -1,5 +1,6 @@
 #
 #  Settings for Fishing
+#  Last updated on ${project.version}-b${BUILD_NUMBER}
 ###
 Fishing:
     LEATHER_BOOTS: