Integrate codecov.

Author: trekhleb

.travis.yml

@@ -3,10 +3,8 @@ dist: trusty
 language: node_js
 node_js:
   - node
-install:
-  - npm i -g eslint codecov
 script:
   - npm run ci
-  - codecov
+  - npm run codecov
 notifications:
   email: false

package-lock.json

@@ -6,7 +6,8 @@
   "scripts": {
     "lint": "eslint ./src/*",
     "test": "jest",
-    "ci": "npm run lint && npm run test"
+    "ci": "npm run lint && npm run test",
+    "codecov": "codecov"
   },
   "repository": {
     "type": "git",
@@ -23,6 +24,7 @@
     "@types/jest": "^22.2.2",
     "babel-cli": "^6.26.0",
     "babel-preset-env": "^1.6.1",
+    "codecov": "^3.0.0",
     "eslint": "^4.19.1",
     "eslint-config-airbnb": "^16.1.0",
     "eslint-plugin-import": "^2.9.0",