Replace harcoded images and documents settings

spec/shared/models/image_validations.rb

@@ -41,7 +41,8 @@ shared_examples "image validations" do |imageable_factory|
   end
 
   it "is not valid for attachments larger than imageable max_file_size definition" do
-    allow(image).to receive(:attachment_file_size).and_return(Image::MAX_IMAGE_SIZE + 1.byte)
+    larger_size = Setting["uploads.images.max_size"].to_i.megabytes + 1.byte
+    allow(image).to receive(:attachment_file_size).and_return(larger_size)
 
     expect(image).not_to be_valid
     expect(image.errors[:attachment]).to include "must be in between 0 Bytes and 1 MB"
@@ -67,4 +68,4 @@ shared_examples "image validations" do |imageable_factory|
     expect(image).not_to be_valid
   end
 
-end
+end