add update custom metadata field method

Author: bishosilwal

lib/imagekitio/client.rb

@@ -152,10 +152,14 @@ def create_custom_metadata_fields(name, label, schema)
       @file.create_custom_metadata(name, label, schema)
     end
 
-    def get_custom_metadata(options = {})
+    def get_custom_metadata_fields(options = {})
       @file.get_custom_metadata(options)
     end
 
+    def update_custom_metadata_fields(id, label, schema)
+      @file.update_custom_metadata(id, label, schema)
+    end
+
     def phash_distance(first, second)
       # Get hamming distance between two phash(image hash) to check
       # similarity between images

lib/imagekitio/file.rb

@@ -232,6 +232,12 @@ def get_custom_metadata(options)
       @req_obj.request('get', url, @req_obj.create_headers, payload)
     end
 
+    def update_custom_metadata(id, label, schema)
+      url = "#{constants.API_BASE_URL}/customMetadataFields/#{id}"
+      payload = { 'label': label, 'schema': schema }
+      @req_obj.request('patch', url, @req_obj.create_headers, payload)
+    end
+
     def validate_upload_options(options)
 
       #  Validates upload value, checks if params are valid,