add support for named db:migrate:undo

[gotrevor]

Solves #350
@bcaudan @theartoflogic

[mention-bot]

@gotrevor, thanks for your PR! By analyzing the history of the files in this pull request, we identified @sdepold, @Americas and @cusspvz to be potential reviewers.

[gotrevor]

Can I get some feedback on this? How active is this repo, and how quickly should I be expecting feedback? @sdepold @Americas @cusspvz

[cusspvz]

cc @mickhansen @janmeier

[mickhansen]

Neither me nor @janmeier have any experience with the CLI.
You likely need @sdepold to take a look.

[cusspvz]

@gotrevor for what I remember from the cli, it seems ok, but as @mickhansen said, you'll gonna need @sdepold opinion.

[gotrevor]

@sdepold @Americas Any chance to get movement on this?

[gotrevor]

@sushantdhiman @sdepold Any chance we could get this merged?

[sushantdhiman]

@gotrevor I am not familiar with CLI code base that much, I will review this PR on weekend and if everything looks good I will merge and release it

[sushantdhiman]

Released in v2.7.0

[vidur149]

@sushantdhiman how to use that undo migration by name

[gotrevor]

@vidur149
Use the --name option to give the name of the migration.
This is listed in the last line of the help:

$ ./node_modules/.bin/sequelize help:db:migrate:undo

Sequelize [Node: 6.10.1, CLI: 2.7.0, ORM: 3.30.4]

COMMANDS
    sequelize db:migrate:undo -- Reverts a migration.
DESCRIPTION
    Reverts a migration.
OPTIONS
    --env              The environment to run the command in. Default: development
    --coffee           Enables coffee script support. Default: false
    --config           The path to the config file. Default: config/config.json
    --options-path     The path to a JSON file with additional options. Default: none
    --migrations-path  The path to the migrations folder. Default: migrations
    --seeders-path     The path to the seeders folder. Default: seeders
    --models-path      The path to the models folder.Default: models
    --url              The database connection string to use. Alternative to using --config files. Default: none
    --name             Name of the migration to undo.