well, better not to do random.choice here.
for my case (in clean system) this scenario run just first, and the removal of os with id==1 just failed:
```
ok
Displays delete for operating system. ... DEBUG ssh:86: LANG=en_US hammer -u admin -p changeme --output csv os list --per-page=10000
DEBUG ssh:89: Id,Name,Release name,Family
2,44czg1 1.1,"",""
1,RedHat 6.5,"",Redhat

DEBUG ssh:86: LANG=en_US hammer -u admin -p changeme os delete --id='1'
ERROR ssh:91: Error: can't convert String into Integer

FAIL
```
Instead please do create a os inside this method (or if you prefer: in setUpClass (@classmethod)) , grep its id and remove that os instead. I assume there is a host (server itself) registered that has a reference to this.