[MIG] marketing_campaign: Migrate to new API

addons/marketing_campaign/__openerp__.py

addons/marketing_campaign/data/marketing_campaign_data.xml

addons/marketing_campaign/data/marketing_campaign_demo.xml

...s/marketing_campaign/data/marketing_campaign_workflow.xml

addons/marketing_campaign/models/ir_actions.py

addons/marketing_campaign/models/mail_template.py

addons/marketing_campaign/models/marketing_campaign.py

addons/marketing_campaign/report/campaign_analysis.py

addons/marketing_campaign/report/campaign_analysis_view.xml

...rketing_campaign/security/marketing_campaign_security.xml

addons/marketing_campaign/test/marketing_campaign.yml

addons/marketing_campaign/tests/__init__.py

.../marketing_campaign/tests/test_marketing_campaign_flow.py

addons/marketing_campaign/views/marketing_campaign_views.xml