Heroku: using newer Maven version (should upgrade to Docker-based workflow soon)

jonashackt · jonashackt · commit 862d4d28fba8 · 2021-05-18T08:30:50.000+02:00
diff --git a/system.properties b/system.properties
@@ -1 +1,2 @@
 java.runtime.version=16
+maven.version=3.6.2
