2019-2: Making the Grade

Write code that, given an array of integer test scores in the inclusive range 0–100, returns an identically-shaped array of the corresponding letter grades according to the below table.

| Score Range | Letter Grade |
| ----------- | ------------ |
| 0–64        | F            |
| 65–69       | D            |
| 70–79       | C            |
| 80–89       | B            |
| 90–100      | A            |