Use umzug as migrator engine
Add task which migrates to new migration structure
Add support for promise based migrations
Improve travis build
Improve wording of help
Enable promisification of migrations by default
Use migrationsWrap instead of promisify
Update to migrations object
Use latest version of umzug
Merge branch 'master' into feature/umzug

Conflicts:
	package.json
Do not remove the file extension
Ensure that db:migrate:old_schema works
Update umzug
Allow late definition of functions
Ensure current meta schema when run db commands
Merge pull request #68 from sequelize/feature/umzug

Use umzug as migrator engine