Resets the image factories each time the collection is called

Former-commit-id: fface1ff6c0c763759e73a03336fe2780dbc7de0
Former-commit-id: 752025603a2c09cfac6ec7125afd59addbd28d4c

src/ImageProcessor.UnitTests/ImageFactoryUnitTests.cs

@@ -668,6 +668,12 @@ namespace ImageProcessor.UnitTests
                 }
             }
 
+            // reset all the images whenever we call this
+            foreach (ImageFactory image in imagesFactories)
+            {
+                image.Reset();
+            }
+
             return imagesFactories;
         }