Actually use new temp directory.

Previously some of the environments tests were creating temporary directories
for environments but still using the default $confdir to find the environments
directory. This patch replaces the use of $confdir with #{tempdir} as I suspect
was intended by the test author. Seems like another solution would be to set
$confdir to the value of #{tempdir} but I'm not sure what the best way to do
that is so there ya have it.

EDIT: I noticed that the reason they used `$confdir` is because in
acceptance/lib/environment_utils.rb there is a method, `use_an_environment`
which sets the `$confdir` value using `puppet master` command line arguments.
This works fine for the MRI puppet master, but won't jive with jvm-puppet since
jvm-puppet must always be started as a system level service, and does not take
the same command line argumetns as the MRI master even when it is started from
the command line, ie using leiningen for development purposes.

Signed-off-by: Wayne <wayne@puppetlabs.com>