Prevent secrets from sending in email
Prevent secrets from sending in email

- Added the methods:
  - setSecretRules: user can configure a set of named rules to test the
    e-mail content;
  - filterSecrets: this method test all the e-mail content with the
    rules configured in setSecretRules, nothing is done if secretRules
    is empty, and if a rule is found in the e-mail content, then a
    exception is thrown;
- The method filterSecrets is called before the request to the API and
  should prevent sensitive data leakage;

sendgrid/sendgrid-nodejs,sendgrid/sendgrid-nodejs,sendgrid/sendgrid-nodejs