[RELEASE][DOC] Archive 0.16 and add 0.17 to navigation bar

[massich]

This PR requires mne-tools/mne-tools.github.io#13

[larsoner]

Might as well bump the version numbers in .circle.yml at the same time

[larsoner]

Oh wait, you haven't bumped the version number to 0.17 yet, nevermind :)

[massich]

No I haven't but maybe I can do it here and I can use this as PR example

[massich]

What have I done wrong?
In this artifact https://10250-1301584-gh.circle-artifacts.com/0/html/index.html it appears to be the dev version but it should not

[larsoner]

This is fine for an intermediate stage. It will look wrong until you push maint/0.17 and bump the master version to 0.18.

[larsoner]

(In other words, as long as you continue to follow the release instructions, it should all work out in the end. There are times/commits for which things are incorrect, like they will be now, because we let CircleCI push website changes, which takes a while, and there are steps in between that we must take.)