W&B logging add hyperparameters (#1399)

* W&B logging add hyperparameters

* hyp bug fix and image logging updates

* if plots and wandb:

* cleanup

* wandb/ gitignore add

* cleanup 2

* cleanup 3

* move wandb import to top of file

* wandb evolve

* update import

* wandb.run.finish()

* default anchors: 3

data/hyp.scratch.yaml

@@ -17,7 +17,7 @@ obj: 1.0  # obj loss gain (scale with pixels)
 obj_pw: 1.0  # obj BCELoss positive_weight
 iou_t: 0.20  # IoU training threshold
 anchor_t: 4.0  # anchor-multiple threshold
-# anchors: 0  # anchors per output grid (0 to ignore)
+# anchors: 3  # anchors per output layer (0 to ignore)
 fl_gamma: 0.0  # focal loss gamma (efficientDet default gamma=1.5)
 hsv_h: 0.015  # image HSV-Hue augmentation (fraction)
 hsv_s: 0.7  # image HSV-Saturation augmentation (fraction)