* tests/crate.scm: Import only sha256 from (gcrypt hash) as gcrypt-sha256 to
prevent a name collision. Rename test 'cargo-recursive-import' to
'crate-recursive-import' and 'cargo-recursive-import-hoors-existing-packages'
to 'crate-recursive-import-honors-existing-packages'. Mock
find-packages-by-name from (gnu packages). Adjust test to import fake 'bar'
crate instead of doctool.
(test-bar-crate): New variable.
(test-bar-dependencies): New variable.
(test-root-crate): Adjust sha256 -> gcrypt-sha256.
(test-doctool-crate,test-doctool-dependencies): Remove variables.
(rust-leaf-bob-3): New variable.
Signed-off-by: Efraim Flashner <efraim@flashner.co.il>