Version in `shard.yml` doesn't match release tag

When I use the following in a program's `shard.yml`:

```yml
dependencies:
  liquid:
    github: amberframework/liquid.cr
 ```

I get the following warning when running `shards update`:

```
Shard "liquid" version (0.4.1) doesn't match tag version (1.0.0)
```

This is because `shard.yml` for `liquid` still says:
```
name: liquid
version: 0.4.1
```