feat(vagrant): add vagrantfile for running docker container

it will run 4 containers - mongo, redis, elastic and superdesk

SD-658
fix(docker): make tests run within container
fix(vagrant): tag superdesk server
spike(workflow) - enable basic modeling for workflow
fix(tests): make file metadata work with elastic
spike(workflow) - move the task inside a dict
Merge pull request #240 from petrjasek/master

feat(vagrant): add vagrantfile for running docker container
spike(workflow) - remove reduntant 'assigned_' from task
Merge pull request #245 from amagdas/workflow_spike

spike(workflow) - enable basic modeling for workflow
fix(celery): make celery pick up broker settings from app
Merge pull request #247 from petrjasek/master

fix(celery): make celery pick up broker settings from app
chore(providers) - decouple how provider can be registered in the system
fix(tasks) - filter and order tasks
Merge pull request #248 from amagdas/chore-providers

chore(providers) - decouple how provider can be registered in the system
Merge pull request #249 from amagdas/fix-tasks

fix(tasks) - filter and order tasks