Merge pull request #1291 from rschamp/fix-preview-deploy

Fix preview deploy

.travis.yml

@@ -38,7 +38,9 @@ deploy:
   api_key: $NPM_TOKEN
 - provider: s3
   on:
-    branch: master
+    branch:
+    - master
+    - $PREVIEW_BRANCH
   access_key_id: $AWS_ACCESS_KEY_ID
   secret_access_key: $AWS_SECRET_ACCESS_KEY
   bucket: $AWS_BUCKET_NAME
@@ -46,3 +48,5 @@ deploy:
   detect_encoding: true
   skip_cleanup: true
   local_dir: build
+after_deploy:
+- 'curl -X POST -H "Fastly-Key: $FASTLY_TOKEN" -H "Accept: application/json" https://api.fastly.com/service/$FASTLY_SERVICE_ID/purge_all'