The "ruby" label was redundant because most our dependencies are ruby
gems. We're still keeping the "javascript" dependencies for npm
dependencies, though.
We originally set a daily interval because we hadn't updated our gem
dependencies for a year.
However, we usually wait a few days/weeks between the time a gem is
released and the moment we update it, and there are gems releasing new
versions every few days, so maintaining daily updates would become
tedious quickly.
So we're now doing it once a month. We're also increasing the limit of
open pull requests so we don't need to worry about whether dependabot is
opening pull requests for every dependency.
Due to a bug in dependabot (see issue 2198 in the
`dependabot/dependabot-core` repository), Dependabot would open pull
requests on every fork, which would be inconvenient.
So we're disabling the updates until this issue is fixed; since we
currently have almost 50 open pull requests, it shouldn't affect us that
much.
