Render charts only once in time scale tests

[benmccann]

In many of the time scale tests, we render the chart and then update it to some certain dimensions. This makes it very difficult to step through the code with a debugger because the first time we hit any line of code doesn't affect the ultimate state of the chart. It also makes the tests take longer to run than necessary.

This passes the dimensions into the creation function so that it's created with the correct dimensions from the beginning.

[kurkle]

I tend to extract tests for debugging, so haven't had this issue.
That said, the only objection I can think of is maybe losing testing of 2nd update to scale with new dimensions, can you check existence / add that kind of test?

[benmccann]

Thanks for taking a look. None of the tests I've changed are testing a 2nd update of scale.

[nagix]

Looks good to me