SVG height and width

I'm using react-primitives-svg to render the same SVG code to both web and sketch:

```
switch (Platform.OS) {
case "sketch":
SvgLib = require("react-primitives-svg/lib/core.sketch");
break;
case "web":
SvgLib = require("react-primitives-svg/lib/core.web");
break;
default: // React Native should be able to pick up `core.ios.js` or `core.android.js` according to the platform
// SvgLib = require("react-primitives-svg");
}
```

Now the SVG height and width seem to be interpreted differently for Sketch and web.
`

Start by comparing the SVG sizing behavior in the core.sketch and core.web entry points using the two viewBox, width, and height examples from the report. Review the related discussion in issue #204 and reproduce both cases; done means the same SVG code renders at consistent dimensions on Sketch and web.

Written by the indexing model from the issue text.