[wip] fix build for the following exception:

lib/bundler/rubygems_integration.rb:172:in `security_policies':
uninitialized constant Gem::Security::Policies (NameError)

from spec: spec/install/gems/dependency_api_spec.rb:479
Merge pull request #2763 from zzak/wip-1-3-failures

[wip] fix build for the following exception: