Updated CI scripts to clean npm cache (#228)

Author: shazron

.travis.yml

@@ -11,7 +11,10 @@ before_install:
 - rm -rf ~/.nvm && git clone https://github.com/creationix/nvm.git ~/.nvm && (cd ~/.nvm
   && git checkout `git describe --abbrev=0 --tags`) && source ~/.nvm/nvm.sh && nvm
   install $TRAVIS_NODE_VERSION
-- node --version  
+- node --version
+- npm --version
+- npm cache clean
+- npm install -g npm@3
 install:
 - npm install
 script:

appveyor.yml

@@ -7,6 +7,8 @@ environment:
 
 install:
   - ps: Install-Product node $env:nodejs_version
+  - npm cache clean
+  - npm install -g npm@3
   - npm install
 
 build: off