added mention of antsBrainExtraction

Author: chrisgorgo

CHANGES

@@ -1,5 +1,6 @@
 Next Release
 ============
+* ENH: New ANTs interface: antsBrainExtraction (https://github.com/nipy/nipype/pull/1231)
 * API: Default model level for the bedpostx workflow has been set to "2" following FSL 5.0.9 lead
 * ENH: New interfaces for interacting with AWS S3: S3DataSink and S3DataGrabber (https://github.com/nipy/nipype/pull/1201)