fix(package.json): move codecov to devDependencies

Author: jedwards1211

package.json

@@ -72,6 +72,7 @@
     "babel-register": "^6.22.0",
     "babel-runtime": "^6.22.0",
     "chai": "^3.5.0",
+    "codecov": "^2.3.0",
     "copy": "^0.3.0",
     "enzyme": "^2.7.0",
     "eslint": "^3.13.1",
@@ -98,7 +99,6 @@
     "react": "0.14.x || ^15.0.0"
   },
   "dependencies": {
-    "codecov": "^2.3.0",
     "prop-types": "^15.0.0"
   }
 }