[github_releases] Use tag name instead of release name (#373)

It is usually simpler to parse, align with the gitmethod, and gives better results by default.

src/github_releases.py

@@ -18,7 +18,7 @@
             if release.is_prerelease:
                 continue
 
-            version_str = release.name
+            version_str = release.tag_name
             version_match = config.first_match(version_str)
             if version_match:
                 version = config.render(version_match)