Possible pending tails since 3.0.0

[puzrin]

If you need one of missed features, just post a message to let us know.

• .test.* improvements
  • Probably we could pop useless data from assertion .stack (no need to trace navit internals when users write tests for applications).
• .pdf()
• .test.class(selector, name)
• ? test css style
• .fill does not supports files