Added an optional ak mode
Merge latest changes.
Base letter range on set goal rather than hard-coded values
merging PR #14
Using 'if' in .travis.yml to be sure it doesn't fail

The short version fails if the condition is not met and thus break the
build.
Merge branch 'JosephRedfern-ak-mode' into master
azmode display fixed for unknown tile values
tests for PR #14
up to date changelog