[Dev Deps] update babel-eslint, eslint, istanbul, mocha

Author: ljharb

package.json

@@ -30,11 +30,11 @@
     "prop-types": "^15.6.0"
   },
   "devDependencies": {
-    "babel-eslint": "^8.0.3",
+    "babel-eslint": "^8.2.1",
     "coveralls": "^3.0.0",
-    "eslint": "^4.12.1",
-    "istanbul": "0.4.5",
-    "mocha": "^4.0.1"
+    "eslint": "^4.18.0",
+    "istanbul": "^0.4.5",
+    "mocha": "^5.0.1"
   },
   "peerDependencies": {
     "eslint": "^3.0.0 || ^4.0.0"