rails 4 compatibllity updates
update readme with rails version info
remove 1.9.2 fromt travis, rails 4 requires 1.9.3 or above
ensure we require protected_attributes
Remove protected_attributes dependency

The protected_attributes gem and strong parameters in Rails 4 don't
play nice together in the same project: protected_attributes
completely takes over the mass assignment sanitization. Since it's
unlikely that transactions will be created from the form parameters
in the first place, this gem does not provide a real benefit.
Merge pull request #20 from sidonath/rails4

Remove protected_attributes for Rails 4
Merge branch 'master' into rails4
update rake version and target rubies for travis
update to require rails 4.0 or greater
Merge branch 'rails4' into develop
updated doc files
update readme compatability
bump version
bump Gemfile version
Merge branch 'release/v0.8.0' into develop