the package manager of nodejs is smoking crack

.travis.yml

@@ -10,10 +10,7 @@ install:
     - sudo npm install -g n
     - sudo n stable
     - sudo ln -sf /usr/local/n/versions/node/8.0.0/bin/node /usr/bin/node
-    - npm install graceful-fs
-    - npm install object-pick
-    - npm install minimatch
-    - npm install esprima
+    - sudo npm update -g
     - npm install gitbook-cli -g
     - npm install gitbook-plugin-autocover
     - npm install gitbook-plugin-github