Add a setting to ignore updates for specific packages

[tjbenton]

Having an option that allows you to ignore updates for specific packages could be very useful. As of today emmet pushed an update(emmet@2.3.15) and that version has a lot of bugs in it, and one of those was that it wouldn't allow me to use the enter key 👎. As you can imagine it makes it impossible to develop. So I installed just ran apm rm emmet; apm install emmet@2.3.14 to install the previous version and everything was back to normal, but then this package updated it automatically 30min later so I had to do it again, and I'll probably have to do it again in 6 hrs.

It's not a huge deal, but in cases like the one with emmet it would be very useful to ignore updates. It would be even better to ignore updates for specific package versions using semver

ignore: ['emmet@2.3.15', 'somepackage@1.3.*, 'etc..']

Just a thought, and thanks for this awesome package. It allows me and my team to have the same packages installed without me having to bug them to update everything.

[timkelty]

👍 I have a package fork I'm running, but I'd like everything else to keep updated.