ci: update coverals script trigger

Author: Scrum

.travis.yml

@@ -1,9 +1,9 @@
 language: node_js
 node_js:
-  - v11
-  - v10
-  - v9
-  - v8
+  - "node"
+  - "lts/*"
+  - 10
+  - 8
 
 after_success:
-  - './node_modules/.bin/nyc report --reporter=text-lcov | ./node_modules/.bin/coveralls'
+  - npm run coverage

package.json

@@ -21,6 +21,7 @@
     "version": "conventional-changelog -i changelog.md -s -r 0 && git commit -am \"build: update changelog\"",
     "prepare": "npm run build",
     "build": "rimraf lib && babel src -d lib",
+    "coverage": "nyc report --reporter=text-lcov | coveralls",
     "pretest": "npm run build",
     "test": "nyc ava"
   },