Maint: Begin adding integration tests for the mount provider
These tests form a starting point for integration testing the mount
provider, using the new Puppet::Util::ExecutionStub mechanism to
simulate the state of the machine in response to the execution of
"mount" and "umount" commands. The tests currently work around some
known bugs (6628, 6632, and 6633).
Reviewed-by: Max Martin <max@puppetlabs.com>