Mock out browser's current timezone

[samselikoff]

Anyone here have experience with mocking out the browser's Timezone API? Timecop.travel works great but we have failing tests on our CI server because of the server's timezone

[samselikoff]

The Timeshift.js library has a simple function that mocks this out:

TimeShift.Date.prototype.getTimezoneOffset = function() { return timezoneOffset; }

@jamesarosen would you be open to a PR that adds this to Timecop.js?

[jamesarosen]

This repo is deprecated and no longer maintained. I thought I put that in the README, but apparently not. I've been using Sinon's date-stubbing, which works well and is well-maintained.