v2.2.3

CHANGES:

Changed

• Minimal OCaml version is now 4.04.

Fixed

• Make colored output and JUnit features more prominent in the documentation.
  (Closes: #13, #12)
• Increase default timeouts, so that they work as well for slow architecture
  like s390x. The fastest timeout is now 20s (immediate test) and the longest
  is 1h (huge test). (Closes: #18)