add inline map to display-inline.js
add display-inline mixin
fix tests
merge display flex + inline-block
Merge remote-tracking branch 'upstream/master' into inline
Drop Node.js 0.8 support from travis.yml

This is consistent with the support scheme for reworkcss/rework,
the conceptual parent repo.
Merge pull request #11 from jamesreggio/inline

Add downlevel IE `display: inline-block` support