Merge ~adam-collard/maas:test-method-refactor into maas:master

src/maasserver/api/tests/test_annotations.py (+6/-6)
src/maasserver/api/tests/test_boot_resources.py (+2/-2)
src/maasserver/api/tests/test_dhcpsnippets.py (+2/-2)
src/maasserver/api/tests/test_discoveries.py (+10/-4)
src/maasserver/forms/tests/test_machinewithmacaddresses.py (+1/-1)
src/maasserver/models/tests/test_bmc.py (+1/-1)
src/maasserver/models/tests/test_interface.py (+3/-2)
src/maasserver/models/tests/test_node.py (+4/-4)
src/maasserver/models/tests/test_sshkey.py (+1/-1)
src/maasserver/models/tests/test_versionedtextfile.py (+1/-1)
src/maasserver/tests/test_listener.py (+1/-1)
src/maasserver/tests/test_preseed.py (+1/-1)
src/maasserver/tests/test_preseed_network.py (+9/-14)
src/maasserver/views/tests/test_account.py (+1/-1)
src/maasserver/websockets/handlers/tests/test_machine.py (+3/-3)
src/maasserver/websockets/tests/test_base.py (+16/-11)
src/metadataserver/tests/test_api.py (+1/-1)
src/provisioningserver/boot/tests/test_windows.py (+1/-1)
src/provisioningserver/dns/tests/test_zoneconfig.py (+2/-2)
src/provisioningserver/tests/test_kernel_opts.py (+1/-1)
src/provisioningserver/utils/tests/test_znums.py (+3/-3)