Bump barracuda version, make our dependencies explicit in the package.json file.

com.unity.ml-agents/CHANGELOG.md

 ## [1.0.3] - 2020-07-07
 ### Minor Changes
 #### com.unity.ml-agents (C#)
+- Update Barracuda to 1.0.2.
+- Explicitly call out dependencies in package.json.
+### Bug Fixes
+#### com.unity.ml-agents (C#)
+#### ml-agents / ml-agents-envs / gym-unity (Python)
+
+## [1.0.3] - 2020-07-07
+### Minor Changes
+#### com.unity.ml-agents (C#)
 - Update Barracuda to 1.0.1. (#4187)
 ### Bug Fixes
 #### com.unity.ml-agents (C#)

com.unity.ml-agents/package.json

   "unity": "2018.4",
   "description": "Use state-of-the-art machine learning to create intelligent character behaviors in any Unity environment (games, robotics, film, etc.).",
   "dependencies": {
-    "com.unity.barracuda": "1.0.2"
+      "com.unity.barracuda": "1.0.2",
+      "com.unity.modules.physics2d": "1.0.0",
+      "com.unity.modules.imageconversion": "1.0.0"
+
   }
 }