🔧 Fix some dependency management.

core/build.gradle

@@ -0,0 +1,17 @@
+plugins {
+    id 'java-library'
+}
+
+archivesBaseName = project.archives_base_name + "-core"
+
+dependencies {
+    api "org.jetbrains:annotations:17.0.0"
+    api "org.aperlambda:lambdajcommon:1.7.2"
+    api "com.electronwill.night-config:core:3.5.3"
+    api "com.electronwill.night-config:toml:3.5.3"
+}
+
+java {
+    sourceCompatibility = JavaVersion.VERSION_1_8
+    targetCompatibility = JavaVersion.VERSION_1_8
+}