Added the option to pass `--save` and `--save-dev`

[MarcelloDiSimone]

Added the option to add --save and --save-dev to the yo bootstrap command in order to save the package as a dependency in bower.json

[sindresorhus]

I don't think it should have these options, but instead default to --save as it's meant to scaffold out something you're going to use in your project. You can easily just install it with whatever flag you want directly with Bower.

// @passy @btford

[passy]

@sindresorhus My thoughts exactly. Just default to using --save. Easy enough to remove it manually if you don't want it.

[sindresorhus]

Alright. PR welcome for that --save change.

[MarcelloDiSimone]

@sindresorhus @passy I thought it might be helpful to leave the choice, since less, sass will be compiled into production code and are therefor part of development. At least I would put them into devDependencies.