Fix nodejs installation issues.

tasks/nodejs.yaml

@@ -6,12 +6,18 @@
       - npm
       - git
 
+- name: check if nodejs binary exists and needs linking to node binary
+  stat: path=/usr/bin/nodejs
+  register: nodejs_bin
+
 - name: link nodejs binary correctly
   file: src=/usr/bin/nodejs dest=/usr/bin/node state=link
+  when: nodejs_bin.exists
 
 - name: install coffeescript + less dependencies
   npm: name={{ item }} global=yes state=present
   with_items:
       - coffee-script
       - less
+      - browserify
       - bower