Remove node-sass requirement that crashes the build

package.json

@@ -63,7 +63,7 @@
     "gulp-htmlmin": "^1.3.0",
     "gulp-inline": "0.0.15",
     "gulp-insert": "^0.5.0",
-    "gulp-sass": "^2.1.1",
+    "gulp-sass": "^6.0.1",
     "gulp-sourcemaps": "^1.6.0",
     "gulp-uglify": "^1.5.2",
     "joi": "^6.10.1",
@@ -78,7 +78,6 @@
     "mocha": "^2.3.4",
     "postcss": "^5.0.14",
     "require-from-string": "^1.1.0",
-    "sassify": "^0.9.1",
     "sinon": "^1.17.3",
     "stringify": "^3.2.0",
     "through": "^2.3.8",