Update README.md

config.ignore accepts strings, not classes
Merge pull request #19 from Slashek/patch-1

Update README.md
Add parameter filtering for POST params
Merge pull request #20 from MindscapeHQ/parameter-filtering

Add parameter filtering for POST params
Bump version for new release
Filtered params over nested hash.
Moved recursive filtering inside the #filter_params method
Merge pull request #21 from blacklane/master

filtered params over nested hash
inherit Rails filter_parameters by default (if available)