4156: Install dependencies to user gempath, not system gempath, even
if not using rvm. Without this, run-tests asks for a sudo password
whenever "bundle install" has any work to do, which is especially
disruptive when two tested components have differing versions of the
arvados gem listed in their Gemfile.lock.
4156: Merge branch 'master' into 4156-bundle-install-user
4156: Fix install destination for gem install --user-install. Make tmp-gem-home discovery work under rvm.
4156: Do not use --user-install -- just install to the GEM_HOME we selected.
4156: Become rvm-aware.
4156: Merge branch 'master' into 4156-bundle-install-user
4156: Move "bundle install" into separate install_ task like apiserver. Remove one more GEMHOME after merge.
4156: Update comments, remove excess cut, tweak GEM_HOME-reporting.
4156: Uninstall old gems just before building new ones. Avoid an extra source of truth for the "gems we install" list.
Merge branch '4156-bundle-install-user' refs #4156