Some packages don't support 3.0+ yet. This fixes this error:
```
Failed to use "phoenix_html" (versions 2.14.0 to 2.14.3) because
unnamed_package (version 0.4.30) requires ~> 2.14
phoenix (version 1.5.10) requires ~> 2.13 or ~> 3.0
vintage_net_wizard (version 0.4.5) requires ~> 3.0
```