Sequelize.ENUM can now take values as arguments or as a single array argument
Fix test to use `field: Sequelize.ENUM` when passing values directly to the type
Moved normalizing of attribute.values to DaoFactory#define
Update changelog.md
Added more tests

Added tests for both field: Sequelize.ENUM and field: { type: Sequelize.ENUM }
Merge pull request #1238 from saschagehlich/bugfix/enum-values

Sequelize.ENUM: Values as arguments / array
Merge branch 'master' into milestones/2.0.0