Use common versions

src/main/kotlin/starter/config/Config.kt

@@ -1,5 +1,6 @@
 package starter.config
 
+import com.electronwill.nightconfig.core.UnmodifiableConfig
 import com.electronwill.nightconfig.core.file.FileConfig
 import starter.*
 import com.electronwill.nightconfig.core.Config as NightConfig
@@ -19,13 +20,19 @@ class Config {
         val cfg = FileConfig.of("config.toml")
         cfg.load()
 
+        @Suppress("UNCHECKED_CAST")
+        val versions = cfg.get<UnmodifiableConfig>("versions").valueMap() as Map<String, String>
+
         val dependencies = cfg.configMap("dependencies")
             .map { (name, values) ->
+                val versionKey: String = values["version"] ?: name
+                val version = versions[versionKey] ?: error("Missing version for $name")
+
                 Dependency(
                     name,
                     values["groupId"],
                     values["artifactId"],
-                    values["version"],
+                    version,
                     values.getOrElse("default", false),
                     values.getEnumOrElse("category", Category.Other),
                     values.getEnumOrElse("scope", Scope.Compile),