Questions about test cases

[lishoulong]

Hi, I have a question about the test cases.

`https://github.com/que-etc/resize-observer-polyfill/blob/master/tests/node/ResizeObserver.spec.node.js`
vs
`https://github.com/que-etc/resize-observer-polyfill/blob/master/tests/ResizeObserver.spec.js`

Now our test case is distributed into two types: bare jasmine and jasmine with karma.

From perspective of concise, I suggest we should merge the above two types into jasmine with karma.

So can someone show me the motivation of this design?