Drop Support for Node 8 (#2290)

Author: IvanGoncharov

.travis.yml

@@ -7,7 +7,6 @@ cache: yarn
 node_js:
   - '12'
   - '10'
-  - '8'
 
 script: |
   if [[ "$(node -pe process.version)" == v12.* ]]; then # Is latest LTS?

package.json

@@ -21,7 +21,7 @@
     "graphql-js"
   ],
   "engines": {
-    "node": ">= 8.x"
+    "node": ">= 10.x"
   },
   "scripts": {
     "test": "npm run prettier:check && npm run lint && npm run check && npm run testonly && npm run check:ts",