rename visualize to visualization

Author: Depu Meng (FA Talent)

README.md

@@ -224,15 +224,15 @@ python tools/train.py \
 #### Visualizing predictions on COCO val
 
 ```
-python visualize/plot_coco.py \
+python visualization/plot_coco.py \
     --prediction [your/prediction/path.json] \
     --save-path [your/path/to/save/figures]
 
 ```
 #### Visualizing predictions on MPII test
 
 ```
-python visualize/plot_mpii.py \
+python visualization/plot_mpii.py \
     --prediction [your/prediction/path.mat] \
     --save-path [your/path/to/save/figures]
 ```