Update helmet config to follow security guidelines

[nsantos16]

References:

• https://github.com/goldbergyoni/nodebestpractices/blob/master/sections/security/secureheaders.md
• https://expressjs.com/en/advanced/best-practice-security.html
• https://itnext.io/how-we-improved-our-node-js-application-security-grade-from-f-to-a-cd42b48192e3

Before and after the implementation check with SSL Labs the grade summary

[Alxzu]

@EMazzaglia @pablanco you implemented this, do you think we're ok with our current config?

[nsantos16]

Let me know if I can help you with something guys, this issue was created based on the SSL Labs grade test(B grade at that time), so maybe is a good start point.