Remove redundant check for duplicate environments (it is not needed since result is a set)
Remove redundant check for duplicate environments (it is not needed
since result is a set)

davidszotten/pytest-django,tomviner/pytest-django,RonnyPfannschmidt/pytest_django,pombredanne/pytest_django,thedrow/pytest-django,bforchhammer/pytest-django,ojake/pytest-django,pelme/pytest-django,ktosiek/pytest-django,reincubate/pytest-django,felixonmars/pytest-django