try short-circuiting with the test statement

Author: cthrax

.travis.yml

@@ -6,10 +6,9 @@ env:
 os:
   - linux
   - osx
-
 script: npm run-script test
 before_install:
-  - if [[ $TRAVIS_OS_NAME == "osx" ]]; then; brew update; brew install nvm; fi
+  - test $TRAVIS_OS_NAME == "osx" && brew update && brew install nvm
   - nvm install $NODE_VERSION
   - npm config set spin false
 install: