Reverse dependencies for opener-build-tools

Latest version of the following gems require opener-build-tools

Gem	Version	Date	Downloads
opener-social-media-classifier +4.07 Thousand Downloads	`1.0.0` May 20, 2014	May 20, 2014	4.07 Thousand
opener-pos-tagger-fr +4.06 Thousand Downloads	`1.0.0` May 20, 2014	May 20, 2014	4.06 Thousand
opener-pos-tagger-it +4.01 Thousand Downloads	`1.0.0` May 20, 2014	May 20, 2014	4.01 Thousand