chore: add support for codecov (#246)

Refs: #240

Author: trivikr

.travis.yml

@@ -6,3 +6,5 @@ install:
   - npm run bootstrap
 script:
   - npm run test
+after_sucess:
+  - ./node_modules/.bin/codecov -f coverage/*.json

package.json

@@ -31,6 +31,7 @@
     "@commitlint/cli": "^7.5.2",
     "@commitlint/config-conventional": "^7.5.0",
     "@types/jest": "^24.0.12",
+    "codecov": "^3.4.0",
     "generate-changelog": "^1.7.1",
     "husky": "^2.1.0",
     "jest": "^24.7.1",