Update elasticsearch to version 6.3.0

Author: depfu[bot]

Gemfile.lock

@@ -104,12 +104,12 @@ GEM
     dotenv-rails (2.7.2)
       dotenv (= 2.7.2)
       railties (>= 3.2, < 6.1)
-    elasticsearch (6.2.0)
-      elasticsearch-api (= 6.2.0)
-      elasticsearch-transport (= 6.2.0)
-    elasticsearch-api (6.2.0)
+    elasticsearch (6.3.0)
+      elasticsearch-api (= 6.3.0)
+      elasticsearch-transport (= 6.3.0)
+    elasticsearch-api (6.3.0)
       multi_json
-    elasticsearch-transport (6.2.0)
+    elasticsearch-transport (6.3.0)
       faraday
       multi_json
     erubi (1.8.0)