Better BigInt support for PostgreSQL.
Added execute() for direct migration per file.
Added: Options containing pre/post/success functions.
Merge pull request #726 from durango/bigint

Better BigInt support for PostgreSQL.
Merge pull request #728 from freezy/execmerge

Make explicit migrations possible.
Updated changelog.
Added basic where logic to sequelize
Cleaned up configuration.spec.js and made Sequelize throw an error for a dialect that doesn't exist. Closes #729.
Merge pull request #733 from durango/no-speak-engrish

Cleaned up configuration.spec.js and made Sequelize throw an error for a dialect that doesn't exist. Closes #729.
Merge pull request #727 from durango/logic

Added basic where logic to sequelize closes #321
Update changelog.md
Merge master