Add product blacklisting mutation (#18)

src/schema.graphql

@@ -382,6 +382,18 @@ input ProductInfoInput {
   visible: Boolean!
 }
 
+input ProductBlacklistingInput {
+  """
+  Only ones used are ProductGroup: PHOTO_WALLPAPER CANVAS WALLPAPER POSTER
+  """
+  marketId: Int!
+  groupIds: [Int]
+}
+
 type Mutation {
   productInfo(productId: Int!, info: ProductInfoInput!): Product
+  productBlacklisting(
+    productId: Int!
+    markets: [ProductBlacklistingInput]
+  ): Product
 }