requests/api/project_spec.rb speed up

**What does this MR do?**
It improves the speed of the `request/api/project_spec.rb` tests by ~3 minutes. It also removes some test duplication, and moves some assertions into the same tests so another API call is not needed.

**Before:** `~3.51 min`
**After:** `~ 50 sec.`
We still validate this by sending no params to the post, it should not be created since we're not giving in the valid information. That validates the behaviour without running unnecessary tests :)