Remove local flag from bundle install

[raesene]

the bundle install command had the --local switch added, meaning that it would not connect to rubygems to try and install gems. As some of the gems are not in the vendor/cache it was failing, causing problems with the install.

So unless there's a specific reason to retain --local, this change suggests removing it.

[etdsoft]

I think the right way around this problem is to make sure all dependencies are in vendor/cache/. The whole point of ./vendor/cache/ is to make sure the repo is self-contained at any given time.

I'll have a look and see what is the stuff we're missing to see if we can add it to the repo.

[raesene]

Fair enough, I think the challenge with that approach is some stuff (like the pdf and prawn stuff) gets pulled in by other gems so bundler misses it.

out of curiousity what's the reckoning on the benefit of the gems being in vendor/cache? Presumably most people installing Dradis are connected to the Internet, so will have access to rubygems, so the traffic volume would be the same.