jvm_binary init handling of name param made more sense before kwargs idiom

...but now it's probably better not to mention it in the sig

Testing Done:
https://travis-ci.org/pantsbuild/pants/builds/35743270

Reviewed at https://rbcommons.com/s/twitter/r/1054/
Fix coverage tests on MacOS

Testing Done:
build-support/bin/ci.sh on my mac laptop.

ci green @ https://travis-ci.org/pantsbuild/pants/builds/35870205

Bugs closed: 595

Reviewed at https://rbcommons.com/s/twitter/r/1057/
Add a CI action to support CI against OSX.

This adds a sync action run on any push to pantsbuild/pants
master that replaces pantsbuild/pants-for-travis-osx-ci master
modifying the active .travis.yml to trigger an OSX CI run.
Prepare pants OSX mirror for CI.