standalone val (#56)

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

.github/workflows/ci.yaml

@@ -93,9 +93,12 @@ jobs:
           echo "TODO"
       - name: Test segmentation
         shell: bash  # for Windows compatibility
+        # TODO: redo val test without hardcoded weights
         run: |
           yolo task=segment mode=train model=yolov5n-seg.yaml data=coco128-seg.yaml epochs=1 img_size=64
+          yolo task=segment mode=val model=runs/exp/weights/last.pt data=coco128-seg.yaml img_size=64
       - name: Test classification
         shell: bash  # for Windows compatibility
         run: |
           yolo task=classify mode=train model=resnet18 data=mnist160 epochs=1 img_size=32
+          yolo task=classify mode=val model=runs/exp2/weights/last.pt data=mnist160