Travis config : Update to gafferDependencies 0.27.0.0.
Travis config : Update to gafferDependencies 0.27.0.0.

ivanimanishi/gaffer,hradec/gaffer,johnhaddon/gaffer,GafferHQ/gaffer,boberfly/gaffer,andrewkaufman/gaffer,johnhaddon/gaffer,lucienfostier/gaffer,andrewkaufman/gaffer,ImageEngine/gaffer,appleseedhq/gaffer,andrewkaufman/gaffer,hradec/gaffer,appleseedhq/gaffer,johnhaddon/gaffer,ivanimanishi/gaffer,lucienfostier/gaffer,chippey/gaffer,boberfly/gaffer,andrewkaufman/gaffer,boberfly/gaffer,GafferHQ/gaffer,chippey/gaffer,chippey/gaffer,ImageEngine/gaffer,lucienfostier/gaffer,appleseedhq/gaffer,GafferHQ/gaffer,GafferHQ/gaffer,johnhaddon/gaffer,hradec/gaffer,GafferHQ/gaffer,ImageEngine/gaffer,andrewkaufman/gaffer,appleseedhq/gaffer,chippey/gaffer,ivanimanishi/gaffer,ImageEngine/gaffer,hradec/gaffer,johnhaddon/gaffer,hradec/gaffer,boberfly/gaffer,lucienfostier/gaffer,ivanimanishi/gaffer