Fix tests for labels
Fix tests for labels

Also, add tests for new bounding box methods.

grigorisg9gr/menpo,menpo/menpo,menpo/menpo,patricksnape/menpo,grigorisg9gr/menpo,yuxiang-zhou/menpo,patricksnape/menpo,yuxiang-zhou/menpo,yuxiang-zhou/menpo,patricksnape/menpo,menpo/menpo,grigorisg9gr/menpo