Explain how to pass record key to forked projects and pull requests

[bahmutov]

On many CIs the environment variables are not passed to the forked projects and pull requests. Thus the npm run test -- --record fails. Example https://travis-ci.org/bahmutov/cypress-react-unit-test/builds/328887786

$ npm test -- --record
> [email protected] test /home/travis/build/bahmutov/cypress-react-unit-test
> cypress run "--record"
You passed the --record flag but did not provide us your Record Key.
You can pass us your Record Key like this:
  cypress run --record --key <record_key>
You can also set the key as an environment variable with the name CYPRESS_RECORD_KEY.
https://on.cypress.io/how-do-i-record-runs
npm ERR! Test failed.  See above for more details.
The command "npm test -- --record" exited with 1.

Need to show how to pass variable, probably limit to encoded variables on TravisCI

[bahmutov]

Hmm, we cannot pass even encrypted value to another repo according to https://docs.travis-ci.com/user/environment-variables/#Encrypting-environment-variables

Maybe a better solution would be for the test runner to

• detect --record flag without record key.
• check if running in a fork pull request (look at environment variables like https://docs.travis-ci.com/user/environment-variables/#Default-Environment-Variables) then show a warning, skip recording but run the tests

cypress-io/cypress#1193