Need to add security headers and CORS policies

[ihernandez-cripto]

As a service provider
I need my service to use security headers and CORS policies
So that my web site is not vulnerable to CORS attacks

Details and Assumptions

* Flask-Talisman will be used for security headers
* Flask-Cors will be used to establish cross-origin resource sharing (CORS) policies    

Acceptance Criteria

gherkin 
Given the site is secured
When a REST API request is made
Then secure headers and a CORS policy should be returned