Remove the now unused istanbul and mocha-lcov-reporter devDependencies

Author: XhmikosR

package-lock.json

@@ -41,11 +41,9 @@
     "request": "^2.88.0"
   },
   "devDependencies": {
-    "nyc": "^14.1.1",
-    "istanbul": "^0.4.5",
     "jshint": "^2.10.3",
     "mocha": "^6.2.2",
-    "mocha-lcov-reporter": "^1.3.0",
+    "nyc": "^14.1.1",
     "should": "^9.0.2",
     "shx": "^0.3.2",
     "sinon-restore": "^1.0.1"