Merge pull request #15455 from twbs/bump-uglify

bump grunt-contrib-uglify to ~0.7.0

package.json

@@ -47,7 +47,7 @@
     "grunt-contrib-jshint": "~0.10.0",
     "grunt-contrib-less": "~0.12.0",
     "grunt-contrib-qunit": "~0.5.2",
-    "grunt-contrib-uglify": "~0.6.0",
+    "grunt-contrib-uglify": "~0.7.0",
     "grunt-contrib-watch": "~0.6.1",
     "grunt-csscomb": "~3.0.0",
     "grunt-exec": "~0.4.6",

test-infra/npm-shrinkwrap.json

@@ -2398,8 +2398,8 @@
       }
     },
     "grunt-contrib-uglify": {
-      "version": "0.6.0",
-      "resolved": "https://registry.npmjs.org/grunt-contrib-uglify/-/grunt-contrib-uglify-0.6.0.tgz",
+      "version": "0.7.0",
+      "resolved": "https://registry.npmjs.org/grunt-contrib-uglify/-/grunt-contrib-uglify-0.7.0.tgz",
       "dependencies": {
         "chalk": {
           "version": "0.5.1",