move istanbul to devDeps

Author: mahboubii

package.json

@@ -33,7 +33,6 @@
 		"async": "^3.2.0",
 		"extend": "^3.0.2",
 		"getstream": "^5.0.0",
-		"istanbul": "^0.4.5",
 		"mongoose": "^5.9.23",
 		"promise": "^8.1.0"
 	},
@@ -44,6 +43,7 @@
 		"eslint": "~4.5.0",
 		"expect.js": "~0.3.1",
 		"glob": "~7.1.2",
+		"istanbul": "^0.4.5",
 		"jscs": "~3.0.7",
 		"mocha": "~3.5.0",
 		"mock-fs": "~4.4.1",