Remove .dev1 suffix for release (#784)

Co-authored-by: ssteinbach <[email protected]>

Author: ssteinbach

setup.py

@@ -280,7 +280,7 @@ def build(self):
 
 # Metadata that gets stamped into the __init__ files during the build phase.
 PROJECT_METADATA = {
-    "version": "0.13.0.dev1",
+    "version": "0.13.0",
     "author": 'Contributors to the OpenTimelineIO project',
     "author_email": '[email protected]',
     "license": 'Modified Apache 2.0 License',