[BREAKING CHANGE] Build: Drop Node 8 and older, require Node 10+

Author: Krinkle

.travis.yml

@@ -1,8 +1,8 @@
 language: node_js
 node_js:
-  - '4' # LTS
-  - '6' # LTS
-  - '7' # Current
+  - '10' # LTS
+  - '12' # LTS
+  - '14' # Current
 script:
   - "npm run build"
   - "npm test"

package.json

@@ -8,6 +8,9 @@
     "type": "git",
     "url": "git+https://github.com/js-reporters/js-reporters.git"
   },
+  "engines": {
+    "node": ">=10"
+  },
   "scripts": {
     "build": "rollup -c",
     "prepublish": "npm run build",