Update utils.py (#620)

Microsoft updated 'Bing Image Search API' which created incompatibility with the search_images_bing() function. The issue is now resolved.

utils.py

@@ -31,12 +31,12 @@ def get_image_files_sorted(path, recurse=True, folders=None): return get_image_f
 from msrest.authentication import CognitiveServicesCredentials as auth
 
 def search_images_bing(key, term, min_sz=128, max_images=150):    
-     params = {'q':term, 'count':max_images, 'min_height':min_sz, 'min_width':min_sz}
+     params = {'q':term, 'count':max_images, 'minHeight':min_sz, 'minWidth':min_sz, 'imageType':'photo'}
      headers = {"Ocp-Apim-Subscription-Key":key}
      search_url = "https://api.bing.microsoft.com/v7.0/images/search"
      response = requests.get(search_url, headers=headers, params=params)
      response.raise_for_status()
-     search_results = response.json()    
+     search_results = response.json()
      return L(search_results['value'])