Adding regression test for vertical text alignment issues
Adding regression test for vertical text alignment issues

This adds two tests for proper vertical alignment of fitted text blocks contents within their block as a whole.

The first test validates that (once at max font size) a text box does not change size when the surrounding block is resized. This failed before this test.

The second test validates that the text box is (more or less) vertically centered within the surrounding block. Combined with the first test, this ensures that the text must be vertically aligned within the block.

Neither test verifies, that the text changes font size correctly when the block is resized. However, the second test happens to validate that the block is correctly aligned after it happens to change font size when resized (but works regardless of the font resizing).

ampproject/amp-toolbox-php,ampproject/amp-toolbox-php