v4.1.1

Bug fixes

• Patch some backward-incompatible changes to validate_presence_of that were
  made in the last version. As of 4.1.0 the presence matcher now checks to
  ensure that empty string will cause the record to be invalid (in addition to
  nil, which it was already checking against). However, this check was being
  performed even if the attribute or column the presence matcher is being run
  against didn't support being set to an empty string. This releases fixes this.
  (#1222, #1224, #1231)