Drop Node 8 and 13 support

Author: bobisjan

.travis.yml

@@ -1,9 +1,8 @@
 language: node_js
 node_js:
-  - "stable"
-  - "12"
   - "10"
-  - "8"
+  - "12"
+  - "14"
 
 env:
   - CXX=g++-4.8 WORKER_COUNT=2

README.md

@@ -27,7 +27,7 @@ particular, you can provide a custom:
 
 ## Requirements
 
-FastBoot App Server requires Node.js v8 or later.
+FastBoot App Server requires Node.js v10 or later.
 
 ## Quick Start
 

package.json

@@ -12,7 +12,7 @@
     "url": "git+https://github.com/ember-fastboot/fastboot-app-server.git"
   },
   "engines": {
-    "node": "8.* || 10.* || >= 12.*"
+    "node": "10.* || 12.* || >= 14"
   },
   "keywords": [
     "ember",