Expose a CocoaPods plugin

[kylef]

Once CocoaPods/CocoaPods#1755 is merged, we can use the post-install hook to enable the settings and user's wont need to add the following the their Podfile's:

begin
  require 'slather'
  Slather.prepare_pods(self)
rescue LoadError
  puts 'Slather has been disabled (not installed).'
end

[marklarr]

Sweeeeet!

[kylef]

Just FYI, I have a work in progress version of this. Going to have to tweak the CocoaPods plugin hook a little bit but this should be ready for 0.34.0 final release.

[marklarr]

You're the best, @kylef!

[ayanonagon]

This is so awesome. 😻