remove old rake task to update version
since we're not using it anymore
(see: https://github.com/rubygems/rubygems.org/pull/629#issuecomment-29638957)
Update newrelic_rpm to version 3.8.0.218
Update rails to version 3.2.18
Update clearance to 1.2.x

Even after removing the references to assign current_user we still get WARNINGS:
'Assigning the current_user this way has been deprecated. You should instead use the sign_in method.'

clearance 1.2.0 includes
https://github.com/thoughtbot/clearance/pull/376 which fixes the
`current_user=` on `sign_in_as`.
Force 1.8.25 rubygems version

The rvm command is not working, as we can see this output from travis:
$ rvm rubygems 1.8.25
Installed rubygems 2.2.2 is newer than 1.8.25 provided with installed ruby, skipping installation, use --force to force installation.

We can use the gem --system command to install a older version
Merge pull request #684 from arthurnn/fix_travis

Force 1.8.25 rubygems version
Merge pull request #683 from arthurnn/update_clearance

Update clearance to 1.2.x
Update cucumber to version 1.3.15
Update cucumber-rails to version 1.4.1
Update rack-maintenance to version 1.2.0
Update librato-rack to version 0.4.5
Update net-ssh to version 2.9.1
Update net-scp to version 1.2.1
Update nokogiri to version 1.6.2.1
Update shoulda-matchers to version 2.6.1
Update dalli to version 2.7.1
Update safe_yaml to version 1.0.3
Update webmock to version 1.18.0
Update unicorn to version 4.8.3
Fix clearance test warning