Update msggen dependencies

Summary:
`msggen` has dependencies on some npm packages with vulnerabilities.
This diff updates the dependency list.

Changelog: [Internal]

Reviewed By: avp

Differential Revision: D19107926

fbshipit-source-id: 0526f6fe430c162322ec9ecb84f3d78604cd76bc

ReactCommon/hermes/inspector/tools/msggen/.babelrc

@@ -1,5 +1,5 @@
 {
-  "presets": [ "flow", ["env", {
+  "presets": [ "@babel/preset-flow", ["@babel/preset-env", {
       "targets": {
         "node": "current"
       }

ReactCommon/hermes/inspector/tools/msggen/package.json

@@ -1,6 +1,7 @@
 {
   "name": "hermes-inspector-msggen",
   "version": "1.0.0",
+  "license": "MIT",
   "bin": {
     "msggen": "./bin/index.js"
   },
@@ -11,16 +12,14 @@
     "test": "jest"
   },
   "devDependencies": {
-    "babel-cli": "^6.26.0",
-    "babel-core": "^6.26.0",
-    "babel-loader": "^7.1.2",
-    "babel-plugin-idx": "^2.0.0",
-    "babel-plugin-syntax-flow": "^6.18.0",
-    "babel-plugin-transform-flow-strip-types": "^6.22.0",
-    "babel-preset-env": "^1.6.0",
-    "babel-preset-flow": "^6.23.0",
-    "jest": "^21.2.1",
-    "webpack": "^3.6.0"
+    "@babel/cli": "^7.2.0",
+    "@babel/core": "^7.2.0",
+    "@babel/plugin-syntax-flow": "^7.2.0",
+    "@babel/plugin-transform-flow-strip-types": "^7.2.0",
+    "@babel/preset-env": "^7.2.0",
+    "@babel/preset-flow": "^7.2.0",
+    "jest": "^24.9.0",
+    "webpack": "^4.41.0"
   },
   "jest": {
     "transform": {