Upgrade es-ruby client to use 5.0.2 which supports correct content-type

Fixes #55

Fixes #57

CHANGELOG.md

@@ -1,3 +1,11 @@
+## 4.0.2
+  - Bump ES client to 5.0.2 to get content-type: json behavior
+  - Revert unneeded manticore change 
+
+## 4.0.1
+  - Switch internal HTTP client to support TLSv1.2
+  - Upgrade ES client internally to better support ES 5.x
+
 ## 4.0.0
   - Remove `scan` from list of options as this is no longer allowed in
     Elasticsearch 5.0.

logstash-input-elasticsearch.gemspec

@@ -1,7 +1,7 @@
 Gem::Specification.new do |s|
 
   s.name            = 'logstash-input-elasticsearch'
-  s.version         = '4.0.0'
+  s.version         = '4.0.2'
   s.licenses        = ['Apache License (2.0)']
   s.summary         = "Read from an Elasticsearch cluster, based on search query results"
   s.description     = "This gem is a Logstash plugin required to be installed on top of the Logstash core pipeline using $LS_HOME/bin/logstash-plugin install gemname. This gem is not a stand-alone program"
@@ -22,7 +22,7 @@ Gem::Specification.new do |s|
   # Gem dependencies
   s.add_runtime_dependency "logstash-core-plugin-api", ">= 1.60", "<= 2.99"
 
-  s.add_runtime_dependency 'elasticsearch', ['>= 1.0.6', '~> 1.0']
+  s.add_runtime_dependency 'elasticsearch', ['>= 5.0.3', '< 6.0.0']
 
   s.add_runtime_dependency 'logstash-codec-json'