do beta versioning on gh action builds

gradle.properties

@@ -0,0 +1,18 @@
+#
+# This file is part of Baritone.
+#
+# Baritone is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Baritone is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with Baritone.  If not, see <https://www.gnu.org/licenses/>.
+#
+
+mod_version = 1.2.15