Bump grunt-contrib-clean to ^0.7.0
Bump grunt-contrib-clean to ^0.7.0

chrismbarr/bootlint,chrismbarr/bootlint,2947721120/ubiquitous-octo-kumquat,2947721120/ubiquitous-octo-kumquat,chrismbarr/bootlint,twbs/bootlint,2947721120/ubiquitous-octo-kumquat,freezy-sk/bootlint,freezy-sk/bootlint,freezy-sk/bootlint,twbs/bootlint