Rename create and delete commands to add and remove

currently to add and remove auth, we use following commands - 

```bash
ee auth create example.com
ee auth delete example.com
```

compared to it, following feels much more intuitive - 

```bash
ee auth add example.com         # adds auth on example.com
ee auth remove example.com      # removes auth on example.com
```

So I think we should be renaming it.