Fix cookie handling - Githubissues

Hey there!

I found an issue with cookie handling so I attempted to fix it. My proposal came out larger than anticipated so let me explain.

Issue description

The resulting .har files included cookies like this:

"cookies": [
  {
    "name": "[\"test",
    "value": "2\"]"
  }
],

Also response objects stored cookies in the respective cookies property that were sent in the Cookie request header instead of the Set-Cookie response headers.

Changes

Dependencies

replaced dependency cookie with set-cookie-parser as the former one is only for parsing Cookie headers, not Set-Cookie headers which are the only ones needing a parser in my proposal

Tests

implemented a mock-server using express as httpstat.us is unavailable more often than not (see https://github.com/aaronpowell/httpstatus/issues/135) and that blocked me writing test code
let tests fail when the expected status code is not present using validateStatus in Axios request config
removed console.log in tests which cluttered test output
included HTTP response headers in tests
implemented cookie tests

Implementation

returnRequestObject(): Cookies now get a special treatment and are not just sent through transformObjectToArray() which was the root cause of the issue.
returnResponseObject():
- Set-Cookie headers are now properly parsed and stored to the cookie property as requested by HTTP Archive format draft
- a request-duration header originally was inserted by the lib which is undesired imho as it could cause downstream issues. Request duration is still included in the time property now.
getCookies() was removed as it is not needed any more in my proposal

Open questions

I also changed checkObj() to not JSON.stringify() arrays any more. I am not sure if this could break something so I'd love to hear opinions on this.
I am open for discussion :)

Thanks for your work on this library!

BeataKr / axios-har-tracker