Update dependencies

Author: naveenkumarsangi

package.json

@@ -51,10 +51,10 @@
   },
   "devDependencies": {
     "chai": "^4.1.2",
-    "coveralls": "^2.13.1",
+    "coveralls": "^3.0.2",
     "istanbul": "^0.4.5",
     "mocha": "^5",
     "mocha-lcov-reporter": "^1.3.0",
-    "sinon": "^3.2.1"
+    "sinon": "^6.1.4"
   }
 }