Wait 10s for ES to come online.

.travis.yml

@@ -14,6 +14,7 @@ before_install:
   - curl -O https://download.elasticsearch.org/elasticsearch/elasticsearch/elasticsearch-0.90.13.zip
   - unzip elasticsearch-0.90.13.zip
   - elasticsearch-0.90.13/bin/elasticsearch
+  - sleep 10
 
   # Run MongoDB as a daemon
   - curl -O https://fastdl.mongodb.org/linux/mongodb-linux-x86_64-3.0.12.tgz