Drop Node.js v6 support (#818)

Node.js v6 will go EOL at the end of April 2019, and already two of the production dependencies of the client have already dropped support for it, and soon others will do *(as well as development dependencies)*.

Furthermore, since Node.js will go in EOL it will never get security patches, plus, also OpenSSL-1.0.2 will go EOL [this year](https://github.com/nodejs/Release#release-schedule); to avoid risks for the client users it is better to drop support for Node.js v6 right away.

Author: delvedor

.ci/test-matrix.yml

@@ -6,6 +6,5 @@ NODE_JS_VERSION:
 - 11
 - 10
 - 8
-- 6
 
 exclude: ~

.npmignore

@@ -67,3 +67,6 @@ scripts
 .ci
 .travis.yml
 certs
+.github
+CODE_OF_CONDUCT.md
+CONTRIBUTING.md

.travis.yml

@@ -5,9 +5,9 @@ sudo: required
 language: node_js
 
 node_js:
+  - "11"
   - "10"
   - "8"
-  - "6"
 
 env:
   global:

README.md

@@ -27,6 +27,8 @@ npm install @elastic/elasticsearch
 
 ### Compatibility
 
+The minimum supported version of Node.js is `v8`.
+
 The library is compatible with all Elasticsearch versions since 5.x, but you should use the same major version of the Elasticsearch instance that you are using.
 ```
 # Elasticsearch 7.x
@@ -40,7 +42,9 @@ The library is compatible with all Elasticsearch versions since 5.x, but you sho
 ```
 
 ## Usage
-You can find the full documentation in the [docs](https://github.com/elastic/elasticsearch-js/tree/master/docs) folder.
+
+You can find the full documentation in our [docs](https://www.elastic.co/guide/en/elasticsearch/client/javascript-api/current/index.html) website.
+
 ```js
 const { Client } = require('@elastic/elasticsearch')
 const client = new Client({ node: 'http://localhost:9200' })
@@ -70,7 +74,9 @@ The returned value of **every** API call is formed as follows:
 }
 ```
 ### Client options
+
 The client is designed to be easily configured as you see fit for your needs, following you can see all the possible options that you can use to configure it.
+
 ```ts
 {
   // the Elasticsearch endpoint to use

docs/breaking-changes.asciidoc

@@ -9,7 +9,7 @@ Every breaking change was carefully weighed, and each is justified. Furthermore,
 
 === Breaking changes
 
-*  Minimum supported version of Node.js is `v6`.
+*  Minimum supported version of Node.js is `v8`.
 
 * Everything has been rewritten using ES6 classes to help users extend the defaults more easily.
 

docs/introduction.asciidoc

@@ -18,6 +18,7 @@ npm install @elastic/elasticsearch
 ----
 
 === Compatibility
+The minimum supported version of Node.js is `v8`.
 
 The library is compatible with all Elasticsearch versions since 5.x, but you should use the same major version of the Elasticsearch instance that you are using.
 ----
@@ -50,4 +51,4 @@ client.search({
 }, (err, result) => {
   if (err) console.log(err)
 })
-----
+----

package.json

@@ -36,33 +36,33 @@
     "company": "Elasticsearch BV"
   },
   "devDependencies": {
-    "@types/node": "^10.12.24",
-    "codecov": "^3.2.0",
-    "convert-hrtime": "^2.0.0",
+    "@types/node": "^11.13.4",
+    "codecov": "^3.3.0",
+    "convert-hrtime": "^3.0.0",
     "dedent": "^0.7.0",
-    "deepmerge": "^3.1.0",
+    "deepmerge": "^3.2.0",
     "dezalgo": "^1.0.3",
-    "js-yaml": "^3.12.1",
+    "js-yaml": "^3.13.1",
     "license-checker": "^25.0.1",
     "lolex": "^3.1.0",
     "minimist": "^1.2.0",
-    "ora": "^3.2.0",
+    "ora": "^3.4.0",
     "pretty-hrtime": "^1.0.3",
     "rimraf": "^2.6.3",
-    "semver": "^5.6.0",
-    "simple-git": "^1.107.0",
+    "semver": "^6.0.0",
+    "simple-git": "^1.110.0",
     "simple-statistics": "^7.0.2",
-    "split2": "^3.1.0",
+    "split2": "^3.1.1",
     "standard": "^12.0.1",
     "stoppable": "^1.1.0",
-    "tap": "^12.6.0",
-    "typescript": "^3.3.3",
+    "tap": "^12.6.1",
+    "typescript": "^3.4.3",
     "workq": "^2.1.0"
   },
   "dependencies": {
     "debug": "^4.1.1",
-    "decompress-response": "^4.0.0",
-    "into-stream": "^4.0.0",
+    "decompress-response": "^4.2.0",
+    "into-stream": "^5.1.0",
     "ms": "^2.1.1",
     "once": "^1.4.0",
     "pump": "^3.0.0"
@@ -76,6 +76,6 @@
     "url": "https://github.com/elastic/elasticsearch-js/issues"
   },
   "engines": {
-    "node": ">=6"
+    "node": ">=8"
   }
 }