[bug]: The generateSrcset can generate broken images

[Jordaneisenburger]

Describe the bug
The util function generateSrcset has the possibility to generate broken images.

if we take a look at the function you can see at line 69 we are dividing a with by a ratio. This works in most cases but when this division doesn't end in a round number we have an issue.

pwa-studio/packages/venia-ui/lib/util/images.js

Lines 59 to 73 in f179f80

	export const generateSrcset = (imageURL, type) => {
	if (!imageURL || !type) return '';
	const generateSrcsetUrl = generateUrl(imageURL, type);
	return Array.from(imageWidths, ([, value]) => value)
	.map(
	width =>
	`${generateSrcsetUrl(
	width,
	width / DEFAULT_WIDTH_TO_HEIGHT_RATIO
	)} ${width}w`
	)
	.join(',\n');
	};

To reproduce
Steps to reproduce the behavior:

1. Go to '...'
2. Click on '....'
3. Scroll down to '....'
4. See error

Expected behavior
It should always give a round number

Screenshots

Possible solutions
add Math.round() around line 69

Please complete the following device information:

• Device [e.g. iPhone6, PC, Mac, Pixel3]:
• OS [e.g. iOS8.1, Windows 10]:
• Browser [e.g. Chrome, Safari]:
• Browser Version [e.g. 22]:
• Magento Version:
• PWA Studio Version:
• NPM version npm -v:
• Node Version node -v:

Please let us know what packages this bug is in regards to:

• venia-concept
• venia-ui
• pwa-buildpack
• peregrine
• pwa-devdocs
• upward-js
• upward-spec
• create-pwa