Add Auth to SW Repo

build.gradle.kts

@@ -1,4 +1,5 @@
 import java.net.URI
+import java.util.Properties
 
 /*
  * This file is a part of the SteamWar software.
@@ -52,6 +53,13 @@ allprojects {
         }
         maven {
             url = URI("https://steamwar.de/maven/")
+            credentials {
+                val swProps = Properties()
+                swProps.load(file("steamwar.properties").inputStream())
+
+                username = swProps.getProperty("maven.username")
+                password = swProps.getProperty("maven.password")
+            }
         }
     }
 }