Adds plugins support to jest.



Adds plugins support to Jest.
Install jest-plugins using yarn:
``shell`
yarn add --dev jest-plugins
In order to utilize jest-plugins in your project, you must configure the setup to add your custom plugins. If jest-plugins ever is merged into jest, then this will be simpler, until then, follow the instructions below.
First, find your jest config which is either in your package.json or in a top-level file called jest.config.js. Add a key setupTestFrameworkScriptFile and point it to another file at the top-level called jest-plugins.js.
Inside jest-plugins.js, write the following:
`javascript`
require('jest-plugins')([
// List all jest-plugins here.
'jest-plugin-action',
'jest-plugin-console-matchers',
'jest-plugin-context',
'jest-plugin-its',
'jest-plugin-set',
'jest-plugin-unhandled-promise',
]);
This is requiring each of the plugins and including it automatically in your project. By design, the setupTestFrameworkScriptFile runs _after_ jest and the test environment have been set up which gives plugins the maximum capabilities to modify the environment.
Once installed, run jest` to run your tests and plugins should be accessible in your test files.