Fix/remove all skipped tests

All skipped tests need to be either fixed or removed from the test suite as practically, no one is every going to check them manually.

This is the list of skipped tests as of 30 April 2018:

• test_image_units_svg.txt … SKIP: Sizes of SVG images are incorrect. They are too small.
• test_issue_216.txt … SKIP: Output PDF is incorrect.
• ~test_issue_238.txt … SKIP: Output PDF is incorrect~
• test_issue_239.txt … SKIP: SVGIMage is backend, but cannot load warning.svg:
• test_issue_255_2.txt … SKIP: headers have keeptogether attribute set, however if the next
• test_issue_266_2.txt … SKIP: Incorrect image
• test_issue_286.txt
• test_issue_303.txt
• ~test_issue_310.txt … SKIP: Line numbers are incorrect (see #662, fixed in #663 & #664)~
• test_issue_312_2.txt … SKIP: Image is too tall for page when width is 80%
• test_issue_337.txt … SKIP: autoLeading: max regression
• test_issue_374.txt … SKIP: Blank page before literal block as block overflows page
• test_issue_378.txt … SKIP: Fails to build PDF: AttributeError: ParaLines instance has no attribute ‘lineBreak’
• test_issue_390.txt … SKIP: --config switch doesn’t work.
• test_issue_419.txt … SKIP: Admonitions have limited styling
• test_issue_467.txt … SKIP: Inline syntax highlighting is not applied
• test_issue_478.txt … SKIP: Tables in blockquotes inside tables have the wrong width
• test_lists.txt … SKIP: Padding issue with 5th level lists
• test_math.txt … SKIP: Vertical alignment issues with formulae
• test_math2.txt … SKIP: Multitple issues with formulae
• test_math_default_role.txt … SKIP: Vertical alignment issues with math role
• test_style_width.txt … SKIP: Table width is incorrect
• test_uml_extension.txt … SKIP: Plantuml not available on Travis as it’s in Ubuntu 16.04+
• sphinx-brokenlinks … SKIP: sphinx-brokenlinks/doc1.pdf is empty
• sphinx-issue251 … SKIP: A different MD5 checksum is created each time
• sphinx-markup … SKIP: cfunc role is not handled correctly

[nfraprado]

I think this a good candidate for Hacktoberfest, as each test should be solved by a different PR. Consider adding a “hacktoberfest” label to this issue so it gains visibility and more people can help 😃. I’m currently looking into the plantuml test.

Also, test_issue_238.txt from that list is not being skipped anymore. And test_issue_286.txt and test_issue_303.txt are two tests that are being skipped but aren’t yet on that list.

[lornajane]

We’ve just added 289 to the ignore list as it needs some attention