[NonGNU ELPA] Org-Drill version 2.7.0

[ELPA update]

Version 2.7.0 of package Org-Drill has just been released in NonGNU ELPA.
You can now find it in M-x package-list RET.

Org-Drill describes itself as:
  Self-testing using spaced repetition

More at https://elpa.nongnu.org/nongnu/org-drill.html