[unity] Added basic Unity package dependencies for spine-unity package. Closes #2628.

spine-unity/Assets/Spine/package.json

@@ -2,7 +2,7 @@
 	"name": "com.esotericsoftware.spine.spine-unity",
 	"displayName": "spine-unity Runtime",
 	"description": "This plugin provides the spine-unity runtime core.",
-	"version": "4.2.87",
+	"version": "4.2.88",
 	"unity": "2018.3",
 	"author": {
 		"name": "Esoteric Software",
@@ -10,6 +10,10 @@
 		"url": "http://esotericsoftware.com/"
 	},
 	"dependencies": {
+		"com.unity.ugui" : "1.0.0",
+		"com.unity.modules.animation" : "1.0.0",
+		"com.unity.modules.physics" : "1.0.0",
+		"com.unity.modules.physics2d" : "1.0.0",
 		"com.esotericsoftware.spine.spine-csharp": "4.2.0"
 	},
 	"repository": {