Update barracuda in the hopes that our burst crashes go away. (#4359) (#4365)

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": "1.0.1"
+    "com.unity.barracuda": "1.0.2"
   }
 }

ml-agents/tests/yamato/yamato_utils.py

     return res.returncode
 
 
+def find_executables(root_dir: str) -> List[str]:
+    """
+    Try to find the player executable. This seems to vary between Unity versions.
+    """
+    ignored_extension = frozenset([".dll", ".dylib", ".bundle"])
+    ignored_files = frozenset(["macblas"])
+    exes = []
+    for root, _, files in os.walk(root_dir):
+        for filename in files:
+            file_root, ext = os.path.splitext(filename)
+            if ext in ignored_extension or filename in ignored_files:
+                continue
+            file_path = os.path.join(root, filename)
+            if os.access(file_path, os.X_OK):
+                exes.append(file_path)
+    return exes
+
+
 def init_venv(
     mlagents_python_version: str = None, extra_packages: Optional[List[str]] = None
 ) -> str: