Fix broken IO.ANSI.Docs parser
Fix IO.ANSI.Docs for multiple stars/underscores/backticks
Use the new build env on Travis

more ram and dedicated cpu cores, better network, faster boot times

http://docs.travis-ci.com/user/workers/container-based-infrastructure/
add 17.3 to allow_failures section
Merge pull request #2925 from joshk/patch-1

Use the new build env on Travis
fix corner case for end detection
add more test cases for in word symbols
Add test cases for non-space delimiters
Merge pull request #2924 from jw2013/italic

Fix broken IO.ANSI.Docs parser
Use IO.ANSI.format/1 for escaping mix shell messages