Filter sensative data when using VCR

filter_sensative_data_in_vcr.md

# test/test_helper.rb
VCR.configure do |config|
  config.filter_sensitive_data('<BROWSERLESS_PRIVATE_KEY>') do |filter|
    Rails.application.credentials.dig(:browserless, :private_key)
  end
end

# test/vcr_cassettes/some_test.yml
---
http_interactions:
- request:
    method: post
    uri: https://chrome.browserless.io/screenshot?token=<BROWSERLESS_PRIVATE_KEY>