add in search of 'N/A'

[NickyDaB]

• working on ib cable inventory does not flag cables with serial_number=N/A #682

Purpose

Address issues in #682

Approach

I believe that UFM restAPIs changed the output of a missing serial number in the most recent update. Previously we searched for NA now it displays as N/A. We now look for both forms in our code.

Future: We need to add in more tests to regression: #686

Origin

@thanh-lam opened #682

How to Test

This section will help the regression tester.

1. Have a cable with a N/A serial number.
2. run inventory on master, this cable will get put into the CSM database.
3. checkout this branch
4. Have a cable with a N/A serial number.
5. run inventory on this branch, this cable will not get put into the CSM database. instead get placed into 'bad_records'

ToDo:

• @pdlun92 run regression. If you have any other questions please ask.

[pdlun92]

Passes regression and unit testing