Can't remove tag's "v" prefix for release_url

I would like to use the release_url link to point to my bintray repository hosting the binaries.
I can't do this because the git tag passed as parameter contains the usual "v" prefix, such as "v1.4", while the bintray url does not:

```
https://bintray.com/joffrey-bion/applications/fx-log/1.4
```

I believe there are many other places where this would be a problem, as the standard git tags include the "v", but the standard artifact version does not.

Start by tracing how release_url receives and formats the Git tag, using the issue's release_url reference as the entry point. Check the related tests, if present, and verify that a tag such as v1.4 can produce a URL using version 1.4 without breaking standard tag links.

Written by the indexing model from the issue text.