Add codecov

Author: frostney

package.json

@@ -66,6 +66,7 @@
     "babel-preset-es2015-loose": "^7.0.0",
     "babel-preset-es2015-loose-rollup": "^7.0.0",
     "babel-register": "^6.7.2",
+    "codecov": "^1.0.1",
     "enzyme": "^2.2.0",
     "eslint": "^2.6.0",
     "eslint-config-airbnb": "^6.2.0",