Enforce node 10

Author: Mark

.travis.yml

@@ -1,6 +1,6 @@
 language: node_js
 node_js:
-    - '8'
+    - '10'
 script:
     - npm test
     - npm run build-dist

package.json

@@ -26,7 +26,7 @@
     "url": "git+https://github.com/mkay581/wait-for-element-transition.git"
   },
   "engines": {
-    "node": ">=8.11.0"
+    "node": ">=10.16"
   },
   "author": "Mark Kennedy <mark@heyimmark.com> (heyimmark.com)",
   "keywords": [