allow appledoc upgrade

[incanus]

Currently we require appledoc 2.2v963 exactly for iOS docs generation. Is this still the case? If not, let's fix that so we can move on.

[1ec5]

Last I checked, the holdup is that newer versions of appledoc come with templates that mimick Apple’s 2014-era docsets. Those templates require JavaScript to work correctly, but Xcode’s Documentation window seems to disallow JavaScript in third-party docsets. This won’t be an issue for the online documentation but will be for those who install the docset in Xcode (which I gather will be relatively few people).

I’d much prefer that we come up with new templates, like the ones used for Mapbox GL JS documentation.

[1ec5]

It’s more likely that we’ll end up switching to jazzy: #3203.

[1ec5]

Bitrise is running appledoc 2.2.1. I just upgraded my machine from 2.2.0 and the templates are broken, which means we’ve been building broken documentation on Bitrise all this time. 2.2.1 comes with an impressive 58 commits.

[1ec5]

The template breakage is tomaz/appledoc#561.