fix HeaderExtractor when using accessor in ActiveRecord

This should fix comma-csv/comma#85
fix quoting for filename on Content-Disposition header
Merge pull request #86 from eitoball/fix_header_extractor_with_accessor_in_active_record

Fix HeaderExtractor when using accessor in ActiveRecord
Fixed a bug which occurs when a polymorphic association has a hash parameter specified
add spec for adad91ac917462a363be5773bd38dbaa2f31ed27
rescue was on the wrong line
Merge pull request #83 from epdejager/polymorphic_associations

Polymorphic Associations with hash parameters
add spec for quoted filename
Merge pull request #87 from astevens/master

fix quoting for filename on Content-Disposition header
update TravisCI configuration

* add ruby 2.1.0
* update Rubinius to use 2.1.1, but allow to fail
* list gemfiles
* use matrix to control builds
update rails and mongoid to lastest
add rails 4.1 gems
update TravisCI config
prepare for releasing version 3.2.1