Fix npm cache issues

wercker.yml

box: wercker/nodejs
# Build definition
build:
  # The steps that will be executed on build
  steps:

    - script:
        name: Reduce NPM cache time
        code: npm config set cache-lock-stale 10000

    - npm-install
    - npm-test

    # A custom script step, name value is used in the UI
    # and the code value contains the command that get executed
    - script:
        name: echo nodejs information
        code: |
          echo "node version $(node -v) running"
          echo "npm version $(npm -v) running"