Add option to only send the modified attributes
Add fix for ruby 1.8.7
Make the option work with other API's
Merge pull request #157 from alfonsocora/send_only_modified_attributes

Add option to only send the modified attributes
There are no changed_attributes for a #find.
Set previously_changed attributes when #save is called.
Always set @changed_attributes to {} after initializing.
Fix spec indentation.
Remove duplicate condition in “or” clause
Remove redefined “respond_to?” method
Merge pull request #183 from remiprev/fix/remove-custom-respond-to

Remove redefined “respond_to?” method
Remove travis tests for ruby-1.8.7
Actually test the send_only_modified_attributes functionality
Merge pull request #184 from remiprev/fix-parse-spec

Actually test the send_only_modified_attributes functionality
Add comment in middleware examples
Show changes for a new record, but not an exiting one.
Merge pull request #182 from centro/master

Set the ActiveModel::Dirty #changed_attributes and #previous_changes correctly.
Failing spec