Print out the depedency tree in case of version_conflict in a child dependency
Rename the method to dependency_tree instead of print_dependency_tree
Merge pull request #2756 from Who828/improve_child_dependency_message

Improve child dependency conflict message
remove fail fast

can't take it anymore. fail fast sends an extra email for every single matrix build, which for Bundler is like 20.
restore dep error indentation
RSpec version conflicts on 1.8 :cold_sweat:
Add a rake task to update SSL Certificates.

Added a rake task under rubygems namespace that updates the SSL
certificates in bundler if they meet either of the following criteria:

a) The filenames do not match that of the certificates in Rubygems
   master
b) Rubygems contains an updated certificate
Do a shallow clone of the remote repository as @fcheung suggested.
Make rubygems:update_certs spec:rubygems:clone_rubygems_master task to remove duplication of logic.
Clean up update_certs

* Extract the logic of identifying when certificates are stale & updating them into CertificateManager
* Delegate the update task in :update_certs to CertificateManager
* Add spec that fails when certificates are out of date leveraging CertificateManager