Remove 'watch' script (#1947)

Modern IDE & editors have specialize pluggings for running Prettier,
ESLint, Flow, etc.
Also since we moved all Mocha options into config file now you can run
subset of tests using 'yarn mocha src/<path to the test file>'

package.json

@@ -22,7 +22,6 @@
     "node": ">= 6.x"
   },
   "scripts": {
-    "watch": "node ./resources/watch.js",
     "test": "npm run lint && npm run check && npm run testonly",
     "test:ci": "yarn check --integrity && npm run lint -- --no-cache && npm run check && npm run testonly:cover && npm run build",
     "testonly": "mocha --full-trace src/**/__tests__/**/*-test.js",
@@ -56,7 +55,6 @@
     "flow-bin": "0.100.0",
     "mocha": "6.1.4",
     "nyc": "14.1.1",
-    "prettier": "1.17.1",
-    "sane": "4.1.0"
+    "prettier": "1.17.1"
   }
 }