###### Motivation for this change


###### Things done

- [ ] Tested using sandboxing
  ([nix.useSandbox](http://nixos.org/nixos/manual/options.html#opt-nix.useSandbox) on NixOS,
    or option `build-use-sandbox` in [`nix.conf`](http://nixos.org/nix/manual/#sec-conf-file)
    on non-NixOS)
- Built on platform(s)
   - [ ] NixOS
   - [ ] macOS
   - [ ] Linux
- [ ] Tested compilation of all pkgs that depend on this change using `nix-shell -p nox --run "nox-review wip"`
- [ ] Tested execution of all binary files (usually in `./result/bin/`)
- [ ] Fits [CONTRIBUTING.md](https://github.com/NixOS/nixpkgs/blob/master/.github/CONTRIBUTING.md).

---


###### Motivation for this change


###### Things done

- [ ] Tested using sandboxing
  ([nix.useSandbox](http://nixos.org/nixos/manual/options.html#opt-nix.useSandbox) on NixOS,
    or option `build-use-sandbox` in [`nix.conf`](http://nixos.org/nix/manual/#sec-conf-file)
    on non-NixOS)
- Built on platform(s)
   - [ ] NixOS
   - [ ] macOS
   - [ ] Linux
- [ ] Tested via one or more NixOS test(s) if existing and applicable for the change (look inside [nixos/tests](https://github.com/NixOS/nixpkgs/blob/master/nixos/tests))
- [ ] Tested compilation of all pkgs that depend on this change using `nix-shell -p nox --run "nox-review wip"`
- [ ] Tested execution of all binary files (usually in `./result/bin/`)
- [ ] Fits [CONTRIBUTING.md](https://github.com/NixOS/nixpkgs/blob/master/.github/CONTRIBUTING.md).

---


Add note about NixOS tests
github/pr-template: Add note about NixOS tests

On several occasions I've seen people bumping packages which have NixOS
tests but without actually running them.

While this probably won't prevent such occasions entirely, at least it
serves as an additional checklist item so contributors don't forget
about these tests.

Signed-off-by: aszlig <ee1aa092358634f9c53f01b5a783726c9e21b35a@redmoonstudios.org>
