TASK: Require latest Neos in travis tests

Author: daniellienert

.travis.yml

@@ -13,7 +13,7 @@ matrix:
       env: ES=5
 
 before_install:
-  - export NEOS_TARGET_VERSION=5.0
+  - export NEOS_TARGET_VERSION=5.1
   - cd ..
   - if [ "$ES" = 5 ]; then wget --no-check-certificate https://artifacts.elastic.co/downloads/elasticsearch/elasticsearch-5.6.15.zip && unzip elasticsearch-5.6.15.zip && mv elasticsearch-5.6.15 elasticsearch; fi
   - cd elasticsearch