feat: only support node 10 and 12 (#24)

BREAKING CHANGE: drop support for node 8

Author: abraham

.travis.yml

@@ -4,8 +4,8 @@ cache: yarn
 notifications:
   email: false
 node_js:
+  - v12
   - v10
-  - v8
 env:
   - PPTR_OVERRIDE_VERSION=1.5.x
   - PPTR_OVERRIDE_VERSION=1.7.x

package.json

@@ -62,5 +62,8 @@
   },
   "peerDependencies": {
     "puppeteer": "^1.5.0 || ^2.0.0"
+  },
+  "engines": {
+    "node": "^10 || ^12"
   }
 }