Add Favicon

[rosspeoples]

I know this is super low priority and somewhat silly, but can we add a favicon? I typically have a bunch of browser tabs open and the tab for Vault-UI can easily get lost since, in Chrome at least, it defaults to using an icon of a curled piece of paper. Having a pretty icon on the tab would improve the UX a bit.

[djenriquez]

Hmmm we do have a favicon though. It looks like its probably unable to find it, meanwhile my browser has had it cached all this time. I'll dig in later today, thanks for catching this.

[tallpauley]

@djenriquez any progress on this? vault-ui points to /favicon.ico which isn't a thing. https://www.vaultproject.io/ has a small and large icon, and a number of platform specific icons (which I don't think we'd need to bother with).

[djenriquez]

Yup, @msessa generously built us a favicon a while back, just had bad references, this fixes it (#188).

[djenriquez]

Closing via #188.