Adds --no-default-migration option diesel_cli

[lgrosz]

Adds --no-default-migration option diesel_cli to disable the generation of the default migration on setup.

This also tweaks the behavior of the db subcommands so they never generate the migration.

[weiznich]

Thanks for working on this. I've added two comments about the reset and setup database command, which should also use the new flag instead of changing the default behaviour.

[lgrosz]

Thanks for working on this. I've added two comments about the reset and setup database command, which should also use the new flag instead of changing the default behaviour.

Sounds good. I can make those changes. Out of curiosity, does it make sense to be creating any migrations during any of the diesel database sub-commands? I was under the impression those commands would setup the database with the existing migrations while diesel setup would be used to "setup" the project, encompassing creating the default migration.

Either way, I'm aware such a behavior change wouldn't belong in a quick patch like this.

[lgrosz]

Sorry for all the updates.. I'm done now.

[weiznich]

I was under the impression those commands would setup the database with the existing migrations while diesel setup would be used to "setup" the project, encompassing creating the default migration.

diesel setup setups your project, which not only includes the database, but also the local folder structure. That includes the default migrations + a default diesel.toml file.