Decimal values for cable lengths are not allowed in bulk edit

[jbakklund]

NetBox version

v3.0.0

Python version

3.7

Steps to Reproduce

1. Navigate to .../dcim/cables/
2. Mark a selection of cables and click on the "Edit Selected" button
3. Set Length to for example, '1.5' and Length unit to 'Meters'

Expected Behavior

According to enhancement #6154, cable lengths should now allow decimal values.

Observed Behavior

NetBox responds with the following warning "Please enter a valid value. The two nearest valid values are 1 and 2."

[sdktr]

CableModel specifies a Decimal:

netbox/netbox/dcim/models/cables.py

Line 77 in db29930

length = models.DecimalField(

The CableBulkEditForm specifies the Integer:

netbox/netbox/dcim/forms.py

Line 4589 in db29930

length = forms.IntegerField(

Can you assign this to me @jeremystretch so I can propose a PR?