* Remove allowTransparency attribute
`allowtransparency` is an Internet Explorer-only attribute that
controls the background transparency of an iFrame. When set to true,
it respects the background color of the iFrame. When set to false, it
sets the background color to that of the document.
This feature was removed in IE9 - falling out of React's support
commitment.
Developers that have somehow figured out how to get IE8 to work with
React 16.x can still use `allowtransparency="true"`, since React now
supports unrecognized attributes.
* Use correct attribute script location
* Use new UMD bundles in attribute fixtures
* Update attribute snapshot
* Blank for CI
* Load ReactDOMServer into attribute table
* Highlight differences between DOM and server renderer
* Use SSR behavior when comparing behavior across renderers
* Use less severe color if SSR differences are only due to warnings
* Ensure result node's tagName matches what's expected
* Throw on unexpected HTMLUnknownElement
* Add ability to "complete" rows and store state in localStorage
* Sort groups based on size
Also: include tagName and containerTagName in info object.
* Tweak sort order
Also canonicalize object results (since these SVG properties are objects).
The canonicalized format is what we compare against.
(This will cause unknown objects to show up as unchanged.)
* Add alphabetical and rev-alphabetical sorting
This is just an initial convenient way to jump to the top or bottom of
the list.
Next we will add a sorting which groups rows together if their behavior
pattern is the same.
* Add sorting to group the rows by behavior pattern
**what is the change?:**
Another sorting option - if the content of a row is the same, it takes
those rows and groups them together.
**why make this change?:**
This will help us find groups of attributes that behave similarly.
**test plan:**
manual testing
* rename variable to be more clear
