Remove ghcapi flag.
Remove scion flag.
Drop upper bound for Cabal library.
Simpify writeB and replaceCharB.
Bump diff lower bound.
Remove dead code.
Fix some warnings.
Updated README.md sandbox instructions for use with cabal 1.20.
Add travis badge to README

The travis badge provides a quick way to view the build status and jump to the travis build result.
Merge pull request #568 from bennofs/travis-badge

Add travis badge to README
Merge remote-tracking branch 'myfork/maintenance'