tests/api: do not test non-existing methods
tests/api: do not test non-existing methods

Remove methods not included in specification (or with different
constraints). Keep commented out methods included in spec but not
implemented.

QubesOS/qubes-core-admin,marmarek/qubes-core-admin,marmarek/qubes-core-admin,QubesOS/qubes-core-admin,QubesOS/qubes-core-admin,marmarek/qubes-core-admin