chore(package): update codecov to version 3.4.0

Closes #48

Author: greenkeeper[bot]

package.json

@@ -82,7 +82,7 @@
     "@types/jasmine": "2.5.53",
     "@types/node": "^8.0.0",
     "camelcase": "^4.0.0",
-    "codecov": "^2.2.0",
+    "codecov": "^3.4.0",
     "codelyzer": "^3.0.1",
     "concurrently": "^3.4.0",
     "core-js": "^2.4.1",