Exclude blender from tests

Maya and Houdini are also excluded, so it seems safe and the sensible
thing to do.

run_maya_tests.py

@@ -42,6 +42,7 @@ if __name__ == "__main__":
 
         "--exclude-dir=avalon/nuke",
         "--exclude-dir=avalon/houdini",
+        "--exclude-dir=avalon/blender",
         "--exclude-dir=avalon/schema",
 
         # We can expect any vendors to

run_tests.py

@@ -23,6 +23,7 @@ if __name__ == "__main__":
         "--exclude-dir=avalon/maya",
         "--exclude-dir=avalon/nuke",
         "--exclude-dir=avalon/houdini",
+        "--exclude-dir=avalon/blender",
 
         # We can expect any vendors to
         # be well tested beforehand.