Automatically upload Carthage.pkg upon tag push

Resolves #160.
Don't do anything for the Travis `install` step
Less verbose curling for WWDR certificate
Don't do anything for Travis `before_install` step
Disable Travis' automatic submodule behaviors

We already do this in script/cibuild, and Travis doesn’t automatically
initialize recursive submodules like we need.
Blow away most of cibuild, just use the Makefile
Merge pull request #225 from Carthage/travis-auto-deploy

Automatically upload package via Travis when a tag is pushed