Raise the minimum NodeJS version to 10 (#84)

.travis.yml

@@ -1,8 +1,8 @@
 language: node_js
 node_js:
-  - "8"
   - "10"
   - "12"
+  - "14"
 
 script:
   - npm run-script lint

README.md

@@ -36,7 +36,7 @@ npx mapscii
 
 ### With npm
 
-If you haven't already got Node.js >= version 6.14, then [go get it](http://nodejs.org/).
+If you haven't already got Node.js >= version 10, then [go get it](http://nodejs.org/).
 
 ```
 npm install -g mapscii

package.json

@@ -16,7 +16,7 @@
     "mapscii": "./bin/mapscii.sh"
   },
   "engines": {
-    "node": ">=8"
+    "node": ">=10"
   },
   "keywords": [
     "map",