Feature separatethousands

[satotake]

related #841
(codepen example)[http://codepen.io/satotake/pen/wWRpbd]
It seems inconsistent that 4-digit numbers on axes such as 3000 has no comma separation while more than 5-digit numbers are separated with commas.

This PR fix this issue.
If explicit flag separatethousands givien to layouts, 4-digit integers are applied to comma separation.

Please review it.
Maybe additional tests are required...

[etpinard]

Great PR. Thanks!

At first, I thought having separators in layout while separatethousands in axis looked a little off. But, I guess, separatethousands is closer to exponentformat, ticksuffixes etc than the global separators. So 👍 there.

Some tests are failing due to the rather strict Lib.coerce design. I'll proposed a solution below the line in question.

It would be nice to add an image test for separatethousands. To do so, add an image test mock JSON in the test/image/mocks/ directory showing off this new functionality. If you're feeling adventurous, you can try to generate the baseline yourself in our image test docker container (docs here).

[etpinard]

Lib.coerce fails if a passed prop (here separatethousands) isn't part of the attribute object used to defined the coerce wrapper function above.

So, we need to make sure that separatethousands is part of all attribute objects that pass through here. I believe this mean adding seperatethousands in:

• colorbar attributes,
• gl3d axis attributes, and
• ternary axis attributes

Moreover, to enable seperatethousands in color bars, you'll need to pass to the mock axis here.

[satotake]

todo

• fix description in layout_attributes
• add mock json
• generate the baseline with docker
• add separatethousands to the other types of graph

[satotake]

All done!

• plotly.js works in html as expected
• test/images/mocks and baseline image added
• CI test passed
  Is this okay for you, @etpinard ?

[etpinard]

@satotake amazing PR. Thanks very much for your efforts. 🍻