Overwrite GitHub releases again

I was under the impression this was causing existing releases to become
drafts again but that happens without this flag.

Author: code-asher

.travis.yml

@@ -31,6 +31,7 @@ deploy:
   - provider: releases
     edge: true
     draft: true
+    overwrite: true
     tag_name: $TRAVIS_TAG
     target_commitish: $TRAVIS_COMMIT
     name: $TRAVIS_TAG