Previously, the vSphere Provider had two methods called
`find_least_used_compatible_host`: one in the base class and one in the vSphere
helper methods. This commit renames the vSphere helper methods and tests to
`find_least_used_vsphere_compatible_host` to stop the conflict.
This commit fixes minor rubocopy violations in eleven source files. Minor
violations are those that include formatting, single quotes, and recently added
classes.
