[jss-vendor-prefixer] clip-path to -webkit-clip-path not working

__Expected behavior:__
When the JSS encounters a clip-path on a webkit browser, it should put a '-webkit-clip-path:' in its place as well.

__Describe the bug:__
There is no change to the CSS. clip-path remains, but will not work with Webkit browsers such as safari.

The JSS
clipPath: 'inset(5px -1px -7px -1px)',

Should result in

'-webkit-clip-path:': 'inset(5px -1px -7px -1px)',

__Codesandbox link:__
Please create a codesandbox.io with the issue. Make it as minimal as possible as this will help us find the bug quicker.

__Versions (please complete the following information):__
- jss: clipPath: 'inset(5px -1px -7px -1px)',
- Browser [e.g. chrome, safari]: Safari & other webkit browsers.
- OS [e.g. Windows, macOS]: MacOS
Feel free to add any additional versions which you may think are relevant to the bug.