Update dependencies, including Babel to v6 and zeroUnits fix.

[bardiharborow]

• jQuery to 3.1.1
• Tether to 1.3.7
• clipboard.js to 1.5.12
• Holder to 2.9.4
• jekyll-search to 1.0.5
• QUnit to 2.0.1
• Anchor to 3.2.2
• Babel to 6.0.0 and include babel-plugin-transform-es2015-modules-strip to replicate v5 modules: ignore behaviour (fixes Upgrade Babel #18212)
• grunt-contrib-cssmin to 1.0.2 and simply IE9 bugfix (fixes Follow-up on clean-css zeroUnits TODO #18144)
• all other NPM dependencies to the latest version
• all Ruby gems to the latest version

[mdo]

How many of these Hound issues are legit? 😆

[bardiharborow]

@mdo none of them 😂. They should clear up once #20446 is merged. This PR overlaps with XhmikosR's #20288 quite significantly, so you may wish to merge that first and then I'll rebase this.

[mdo]

@bardiharborow Just merged that PR :D. Let's see if this gets updated and we can get it merged in, then deal with any overlap later.

[wolfy1339]

You will need to rebase the PR to get Hound to clear the issues

[bardiharborow]

@mdo it's all green now. 😄

[mdo]

😻 Thanks!

[bardiharborow]

@mdo, it appears there were side effects to this and now travis builds are crashing, which is very weird given that the build of the PR itself passed. Root cause is npm/npm#14042, something to do with me shrink-wrapping on a mac.

[bardiharborow]

@mdo, fix is at fc2a11d. I'm still none the wiser as to how the PR build passed but branch builds aren't.