upgrade barracuda to 1.0.0 (#4118)

com.unity.ml-agents/CHANGELOG.md

 ### Minor Changes
 #### com.unity.ml-agents (C#)
 - `RayPerceptionSensor.Perceive()` now additionally store the GameObject that was hit by the ray. (#4111)
+- The Barracuda dependency was upgraded to 1.0.0 (#4118)
 #### ml-agents / ml-agents-envs / gym-unity (Python)
 - Added new Google Colab notebooks to show how to use `UnityEnvironment'. (#4117)
 

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": "0.7.1-preview"
+    "com.unity.barracuda": "1.0.0"
-}
+}