Update ElasticsearchDriverTest.java

Fix typo
Merge pull request #1 from anthonycorbacho/patch-1

Update ElasticsearchDriverTest.java
Add gradle build file
Fixing gradle build warnings
Merge pull request #2 from NFLabs/fixing-gradle-build-warning

Fixing gradle build warnings
.gitignore updated to exclude build artifacts
Add travis CI
Merge branch 'master' of github.com:NFLabs/zeppelin-driver-elasticsearch
Add build status image and set proper jdk
Merge branch 'master' into update_driver_api