add quotes around curl url for known releases
add quotes around curl url for known releases

I ran `kiex implode` then reinstalled kiex, and my `kiex list known` stopped working for some reason. Upon fiddling with the curl command on my command line I discovered this fix:

I get this output when I run the curl manually:
```
\curl -i ${AUTH_HEADER[*]} -H "User-Agent: $USER_AGENT" -H 'Accept: application/json' -qs https://api.github.com/repos/elixir-lang/elixir/releases?per_page=100 | tr ',' '\n' | grep '"tag_name":'
zsh: no matches found: https://api.github.com/repos/elixir-lang/elixir/releases?per_page=100
```
But when I add quotes...
```
\curl -i ${AUTH_HEADER[*]} -H "User-Agent: $USER_AGENT" -H 'Accept: application/json' -qs "https://api.github.com/repos/elixir-lang/elixir/releases?per_page=100" | tr ',' '\n' | grep '"tag_name":'
"tag_name":"v1.7.3"
"tag_name":"v1.7.2"
...
```
taylor/kiex