make sure ._ osx files are properly ignored

dashboard-ui/bower_components/iron-flex-layout/.travis.yml

@@ -0,0 +1,28 @@
+language: node_js
+sudo: false
+matrix:
+  include:
+  - node_js: stable
+    script: xvfb-run wct
+    addons:
+      firefox: latest
+      apt:
+        sources:
+        - google-chrome
+        packages:
+        - google-chrome-stable
+  - node_js: node
+    script:
+    - |
+      if [ "${TRAVIS_PULL_REQUEST}" = "false" ]; then
+        wct -s 'default'
+      fi
+before_script:
+- npm install web-component-tester
+- npm install bower
+- export PATH=$PWD/node_modules/.bin:$PATH
+- bower install
+env:
+  global:
+  - secure: jFaXkmco40NlJT4VyFYM34Zv9D1XVfLXgixobnyHQyJDBKSXrNLcwDuvrGUpJx/pwBCxEhKAbvxeJ+PBMUv8QV08MAdw2S6QOsIe3CUxAehoNoOMJw5duhE8faWlz8qzmCWEowHVFUeVsd0ZUsgOu6RTspj2A51D/CztQuW0Ljw=
+  - secure: fKrO5yMx8kZM1WQ3k0bzo6MCREKGW2WkCl2suDjuEtb1SQ/SaZa9Tun0fcqIHVJqg9+jOS1Romt/+MN27Nc6IT1tv/NdLd+uWjtMA+OzLyv48gzcdu8Ls/TISUGm5Wb7XHkcvMAb1tRoBs5BOvQ/85FilZLEq1km8snG9ZsOOWI=