Fixe les numéros de dépendances Node.js

package.json

@@ -22,21 +22,21 @@
   },
   "homepage": "https://github.com/zestedesavoir/zds-site",
   "dependencies": {
-    "autoprefixer": "^6.1.0",
+    "autoprefixer": "6.1.0",
     "cookies-eu-banner": "1.2.7",
-    "cssnano": "^3.3.2",
+    "cssnano": "3.3.2",
     "del": "2.0.2",
     "gulp": "3.9.0",
     "gulp-concat": "2.6.0",
     "gulp-if": "2.0.0",
     "gulp-imagemin": "2.3.0",
     "gulp-load-plugins": "1.0.0",
     "gulp-notify": "2.2.0",
-    "gulp-postcss": "^6.0.1",
+    "gulp-postcss": "6.0.1",
     "gulp-rename": "1.2.2",
     "gulp-sass": "2.0.4",
     "gulp-size": "2.0.0",
-    "gulp-sourcemaps": "^1.6.0",
+    "gulp-sourcemaps": "1.6.0",
     "gulp-uglify": "1.4.2",
     "jquery": "2.1.4",
     "normalize.css": "3.0.3",