Fix travis to use next version of npm

npm 2.7.5 apparently broke something with node 0.8.
Need to use 2.7.6 for the time being

npm/npm#7849

Author: eddiezane

.travis.yml

@@ -5,8 +5,7 @@ node_js:
 - "0.11"
 - "0.12"
 before_install:
-- '[ "${TRAVIS_NODE_VERSION}" != "0.8" ] || npm install -g [email protected]'
-- npm install -g npm@latest
+- npm install -g npm@next
 notifications:
   hipchat:
     rooms: