Clear CPATH env variable in Travis

Author: kylefleming

.travis.yml

@@ -8,6 +8,7 @@ install:
 - bundle install --jobs=3 --retry=3 --path=${BUNDLE_PATH:-vendor/bundle}
 - bundle exec pod setup
 before_script:
+- export CPATH=
 - printenv
 script:
 - rake install