Update dependency-graph to version 0.8.0 (#253)

Author: greenkeeper[bot]

package.json

@@ -20,7 +20,7 @@
   "dependencies": {
     "chalk": "^2.1.0",
     "chokidar": "^2.0.0",
-    "dependency-graph": "^0.7.0",
+    "dependency-graph": "^0.8.0",
     "fs-extra": "^7.0.0",
     "get-stdin": "^6.0.0",
     "globby": "^8.0.0",