refactor: update tooling, add support for Cordova v9

Author: timbru31

.editorconfig

@@ -6,3 +6,4 @@ indent_size = 2
 end_of_line = lf
 charset = utf-8
 trim_trailing_whitespace = true
+insert_final_newline = true

.eslintrc

@@ -0,0 +1,6 @@
+{
+    "extends": "standard",
+    "rules": {
+      "semi": [2, "always"]
+    }
+}

.eslintrc.json

@@ -1,3 +1,3 @@
 node_modules
 npm-debug.log
-*.orig
+*.orig

.gitignore

@@ -1,5 +1,6 @@
 language: node_js
 sudo: false
 node_js:
-  - "4"
   - "6"
+  - "8"
+  - "10"

.travis.yml

@@ -1,6 +1,6 @@
 [![npm version](https://badge.fury.io/js/cordova-plugin-add-swift-support.svg)](https://badge.fury.io/js/cordova-plugin-add-swift-support) [![Build Status](https://travis-ci.org/akofman/cordova-plugin-add-swift-support.svg?branch=master)](https://travis-ci.org/akofman/cordova-plugin-add-swift-support) [![npm](https://img.shields.io/npm/dm/cordova-plugin-add-swift-support.svg)]()
 
-# cordova-plugin-add-swift-support 
+# cordova-plugin-add-swift-support
 
 ![swift-128x128](https://cloud.githubusercontent.com/assets/579922/15999501/79196b48-3146-11e6-836e-061a7ef53571.png)
 
@@ -16,13 +16,13 @@ Or add it as a dependency into your own plugin:
 
 `<dependency id="cordova-plugin-add-swift-support" version="1.7.2"/>`
 
-By default, the Swift 3 support is added but the legacy version (2.3) can still be configured as a preference, inside the project's `config.xml`, within the `<platform name="ios">` section:
+By default, the Swift 4 support is added but the legacy version (2.3) can still be configured as a preference, inside the project's `config.xml`, within the `<platform name="ios">` section:
 
 `<preference name="UseLegacySwiftLanguageVersion" value="true" />`
 
 Or it is possible to specify the version as following, inside the project's `config.xml`, within the `<platform name="ios">` section:
 
-`<preference name="UseSwiftLanguageVersion" value="4" />`
+`<preference name="UseSwiftLanguageVersion" value="5" />`
 
 If needed, add a prefixed Bridging-Header file in your plugin in order to import frameworks (MyPlugin-Bridging-Header.h for instance).
 As an example you can have a look at this [plugin](https://github.com/akofman/cordova-plugin-permissionScope).
@@ -31,8 +31,7 @@ If the `cordova-plugin-add-swift-support` plugin is already installed to your pr
 
 ## Contributing
 
-The src folder contains ECMAScript 2015 source files.
-This project is built and bundled using [Babel](https://babeljs.io/) and [Webpack](https://webpack.js.org/).
+The src folder contains ECMAScript 2015 source files, the minimum Node.js version is `6` (Boron).
 
 ## License