no version for rails dev dependency
softer rails dependency
drop 1.8.7 and 1.9.2 from travis
just test ruby 1.9.3
update rspec dependency
support testing against both rails 3.2+ and 4.0
travis test matrix for rails versions
test both rails 4.0 and 4.1
update README [ci skip]
Merge pull request #4 from challengepost/activeasync_for_rails4

expand rails dev dependency to support rails 4+