Remove zincutils tests.
Review Request #2149 - Created May 1, 2015 and submitted
|davidt, patricklaw, stuhood|
They are a subset of the tests in pantsbuild/zincutils, and it's
pointless and annoying to maintain them in both places.
If/when we move that code back into this repo we will move the tests
back too of course.
CI passes: https://travis-ci.org/pantsbuild/pants/builds/60866256