Renaming "hostname" to "HOSTNAME" throws an error

I'm trying to rename the ```hostname``` attribute of class CloudHost to ```HOSTNAME``` but after the ```dev_ralph migrate``` command I'm running into the below issue. Same is the case on adding custom attributes like ```TAGS``` and ```REMARKS```

```
File "/Users/mketan/Documents/ralph/ralph_env/lib/python3.6/site-packages/MySQLdb/connections.py", line 276, in query
_mysql.connection.query(self, query)
django.db.utils.IntegrityError: (1062, "Duplicate entry '115-view_cloudhost_HOSTNAME_field' for key 'content_type_id'")
```

**Modified Code**

```
# cloudflavor = models.ForeignKey(CloudFlavor, verbose_name='Instance Type')
# cloudprovider = models.ForeignKey(CloudProvider)
# cloudprovider._autocomplete = False
#
# host_id = models.CharField(
# verbose_name=_('host ID'),
# unique=True,
# max_length=100
# )
# hypervisor = models.ForeignKey(DataCenterAsset, blank=True, null=True)
# image_name = models.CharField(max_length=255, null=True, blank=True)
HOSTNAME = models.CharField(
verbose_name=_('hostname'),
max_length=255
)

IP = models.CharField(max_length=255, default=None)
# HOSTNAME = models.CharField(max_length=255, default=None)
NAME = models.CharField(max_length=255, default=None)
APPLICATION = models.CharField(max_length=255, default=None)
CORES = models.CharField(max_length=255, default=None)
MEMORY = models.CharField(max_length=255, default=None)
SITE = models.CharField(max_length=255, default=None)
ENV = models.CharField(max_length=255, default=None)
DESCRIPTION = models.CharField(max_length=255, default=None)
TAGS = models.CharField(max_length=255, default=None)
REMARKS = models.CharField(max_length=255, default=None)
```