fixed all content-view tests

Few small fixes, due to which some of the tests were failing:

- repo and `published-name` was uniqueifying twice
- remove `pub-name` variable and fetching `published-name` from cv
- client operations were failing since -y was missing to yum command
- calling `promote-published-content-view` with `let` instead of `with-unique`

Now all tests are working fine.