Improve compatibility of data-srcset with older browsers (#143)
Improve compatibility of data-srcset with older browsers (#143)

**Issue: #142**

The direct manipulation of an attribute like `srcset` is only possible for supported attributes. The `srcset` attribute is not supported in older browsers, including IE9-11. Using `setAttribute()` will work for older browsers as well.
ApoorvSaxena/lozad.js