chore(typescript): remove typings

Author: alexkrolick

package.json

@@ -4,7 +4,6 @@
   "description": "Simple and complete React DOM testing utilities that encourage good testing practices.",
   "main": "dist/index.js",
   "module": "dist/react-testing-library.esm.js",
-  "typings": "typings/index.d.ts",
   "engines": {
     "node": ">=8"
   },
@@ -24,7 +23,6 @@
   },
   "files": [
     "dist",
-    "typings",
     "cleanup-after-each.js"
   ],
   "keywords": [
@@ -47,7 +45,6 @@
   },
   "devDependencies": {
     "@reach/router": "^1.2.1",
-    "@types/react-dom": "^16.0.9",
     "axios": "^0.18.0",
     "eslint-import-resolver-jest": "^2.1.1",
     "history": "^4.7.2",