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.`
> should return a 400 error if code not give

I think validation of each attribute should be tested in models. API should test cases like `valid` or `invalid` object