[Validator] Image Constraint - minPixels and maxPixels should be float

Author: wkania

reference/constraints/Image.rst

@@ -341,7 +341,7 @@ Parameter             Description
 ``maxPixels``
 ~~~~~~~~~~~~~
 
-**type**: ``integer``
+**type**: ``float``
 
 If set, the amount of pixels of the image file must be less than or equal to this
 value.
@@ -465,7 +465,7 @@ Parameter             Description
 ``minPixels``
 ~~~~~~~~~~~~~
 
-**type**: ``integer``
+**type**: ``float``
 
 If set, the amount of pixels of the image file must be greater than or equal to this
 value.