Make sure all Task mixins are on the left.
Review Request #2421 - Created June 26, 2015 and submitted
|davidt, nhoward_tw, zundel|
Note that tasks that extend NailgunTask cannot have JvmToolTaskMixin on the left, because NailgunTask is already a JvmToolTaskMixin, and this leads to a "Cannot create a consistent method resolution order (MRO)" error. But the solution is simply not to explicitly mix in JvmToolTaskMixin, and rely on inheriting it from NailgunTask.
CI passes: https://travis-ci.org/pantsbuild/pants/builds/68404283.