Update frontend.key

Make clear this is a test key
Use feedback tab not popup
Merge pull request #2516 from guardian/userzoom-feedback-tab

Use feedback tab not popup
Update frontend.crt

Be clear this is just for local development
Slight problem with detroy on component
Merge pull request #2517 from guardian/discussion-cancel-reply

#DIS-1371 #looks fixed to me, merging in.
Show feedback tab instantly
Merge pull request #2518 from guardian/userzoom-feedback-tab

Userzoom: feedback tab on 1st uk-aplha visit