TASK: Update travis.yml to use ElasticSearch 2.4.1

Author: dfeyer

.travis.yml

@@ -7,8 +7,8 @@ matrix:
 sudo: false
 before_install:
   - cd ..
-  - wget --no-check-certificate https://download.elastic.co/elasticsearch/elasticsearch/elasticsearch-1.7.5.zip && unzip elasticsearch-1.7.5.zip
-  - mv elasticsearch-1.7.5 elasticsearch
+  - wget --no-check-certificate https://download.elastic.co/elasticsearch/release/org/elasticsearch/distribution/zip/elasticsearch/2.4.1/elasticsearch-2.4.1.zip && unzip elasticsearch-2.4.1.zip
+  - mv elasticsearch-2.4.1 elasticsearch
   - cd elasticsearch
   - bin/elasticsearch -d
   - cd ..