Add option to run test suite in incognito mode

[dima117]

#28

In incognito mode, Chrome doesn't write any user data to disk. This can lead to significant speedups with test suites that use features like IndexedDB.

Note that when incognito is enabled, this will open two windows (one incognito and one non-incognito). I couldn't figured out how to suppress this behavior. It should be harmless though.

[dima117]

I was fixed the promlem and publish new package v2.0.1.

[lambda-fairy]

Thanks! I am busy right now, but will test this when I get the time.