chore: Dropped support of Node.js 4

Some NPM dependencies dropped support of Node.js 4. It is easier to drop it
too, that looking for workarounds to get the testing build running, or claim
the support without actually testing it.

Add testing with Node.js 10.

BREAKING CHANGE: Dropped support of Node.js 4

.travis.yml

@@ -6,16 +6,16 @@ cache:
 notifications:
   email: false
 node_js:
+  - '10'
   - '8'
   - '6'
-  - '4'
 before_install:
   - npm install -g npm
 before_script:
   - npm install -g grunt-cli
   - npm prune
 after_success:
-  - npm run semantic-release
+  - npm run travis-deploy-once "npm run semantic-release"
 branches:
   except:
     - /^v\d+\.\d+\.\d+$/

LICENSE

@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2017 Ferdinand Prantl
+Copyright (c) 2017-2018 Ferdinand Prantl
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

README.md

@@ -185,6 +185,7 @@ your code using Grunt.
 
 ## Release History
 
+ * 2018-04-27   v1.0.0   Dropped support of Node.js 4
  * 2017-11-08   v0.1.3   Upgrade npm module dependencies
  * 2017-05-09   v0.1.0   Move multiple files in the scope of one task
  * 2017-04-09   v0.0.6   Fix async dependency
@@ -193,7 +194,7 @@ your code using Grunt.
 
 ## License
 
-Copyright (c) 2017 Ferdinand Prantl
+Copyright (c) 2017-2018 Ferdinand Prantl
 
 Licensed under the MIT license.
 

package.json

@@ -30,14 +30,15 @@
     "test": "grunt",
     "check_coverage": "GRUNT_MOVE_COVERAGE=1 grunt",
     "post_coverage": "GRUNT_MOVE_COVERAGE=1 grunt default coveralls",
-    "semantic-release": "semantic-release"
+    "semantic-release": "semantic-release",
+    "travis-deploy-once": "travis-deploy-once"
   },
   "dependencies": {
     "async": "~2.6.0",
-    "chalk": "^2.3.0"
+    "chalk": "^2.4.1"
   },
   "devDependencies": {
-    "grunt": "^1.0.1",
+    "grunt": "^1.0.2",
     "grunt-continue-ext": "^1.0.0",
     "grunt-contrib-clean": "^1.1.0",
     "grunt-contrib-copy": "^1.0.0",
@@ -47,7 +48,8 @@
     "grunt-istanbul": "^0.8.0",
     "jshint-stylish": "^2.2.1",
     "time-grunt": "^1.4.0",
-    "semantic-release": "^15.0.0"
+    "semantic-release": "^15.1.7",
+    "travis-deploy-once": "^4.4.1"
   },
   "keywords": [
     "gruntplugin",