Drop support for node < 6

.babelrc

@@ -5,7 +5,7 @@
       {
         "useBuiltIns": true,
         "targets": {
-          "node": "4.8"
+          "node": "6.9.0"
         },
         "exclude": [
           "transform-async-to-generator",

.travis.yml

@@ -14,10 +14,6 @@ jobs:
       node_js: 6
       env: WEBPACK_VERSION=latest JOB_PART=test
       script: npm run travis:$JOB_PART
-    - <<: *test-latest
-      node_js: 4.8
-      env: WEBPACK_VERSION=latest JOB_PART=test
-      script: npm run travis:$JOB_PART
     - <<: *test-latest
       node_js: 8
       env: WEBPACK_VERSION=latest JOB_PART=lint

appveyor.yml

@@ -11,9 +11,6 @@ environment:
     - nodejs_version: '6'
       webpack_version: latest
       job_part: test
-    - nodejs_version: '4.3'
-      webpack_version: latest
-      job_part: test
 build: 'off'
 matrix:
   fast_finish: true

example/.babelrc

@@ -5,7 +5,7 @@
       {
         "useBuiltIns": true,
         "targets": {
-          "node": "4.8"
+          "node": "6.9.0"
         },
         "exclude": [
           "transform-async-to-generator",

package.json

@@ -53,7 +53,7 @@
     "webpack-defaults": "^1.6.0"
   },
   "engines": {
-    "node": ">= 4.8 < 5.0.0 || >= 5.10"
+    "node": ">= 6.9.0 <7.0.0 || >= 8.9.0"
   },
   "peerDependencies": {
     "webpack": "^2.0.0 || ^3.0.0 || ^4.0.0"