Fix intermitent bug with npm locks

.travis.yml

@@ -5,12 +5,14 @@ python:
 cache:
   directories:
     - $HOME/.wheelhouse/
+before_install:
+  - rm -rf ~/.npm
+  - mkdir ~/.npm
 install:
   - pip wheel -w $HOME/.wheelhouse -f $HOME/.wheelhouse -r requirements.txt
   - pip install --find-links=$HOME/.wheelhouse --no-index -rrequirements.txt
   - python setup.py install
   - cd dashed/assets
-  - "touch $HOME/.npm/foo.lock; rm -f $HOME/.npm/*.lock"
   - npm install
   - npm run prod
   - cd $TRAVIS_BUILD_DIR