This adds a special package type to Spack which is used to aggregate
a set of packages that a user might commonly install together; it
does not include any source code itself and does not require a
download URL like other Spack packages. It may include an 'install'
method to generate scripts, and Spack will run post-install hooks
(including module generation).
* Add new BundlePackage type
* Update the Xsdk package to be a BundlePackage and remove the
'install' method (previously it had a noop install method)
* "spack create --template" now takes "bundle" as an option
* Rename cmd_create_repo fixture to "mock_test_repo" and relocate it
to shared pytest fixtures
* Add unit tests for BundlePackage behavior
c9e214f6d3