Disallow throwing non-error objects

Summary: It's annoying to have to treat things like they might not be errors, inside catch blocks. This should stop that.

Reviewed By: passy

Differential Revision: D16201509

fbshipit-source-id: b028ea3a1e0766763fcf2659d80456f4dd281c40

.eslintrc.js

@@ -30,6 +30,7 @@ module.exports = {
     'no-console': 0, // we're setting window.console in App.js
     'no-multi-spaces': 2,
     'prefer-promise-reject-errors': 1,
+    'no-throw-literal': 'error',
     'no-extra-boolean-cast': 2,
     'no-extra-semi': 2,
     'no-unsafe-negation': 2,