Test to exercise lustre code.

Add a new test that verifies FS type is lustre when CHPL_AUX_FILESYS
contains lustre.

At present, the SKIPIF functionality does not work for something like: skip if
CHPL_AUX_FILESYS does not contain "lustre" (I believe). It is possible to
say: skip if MY_VAR contains "some value". There needs to be some way
to indicate the latter in order for thi tests to be included in nightly runs.