Run bundle install to be sure to use the updated version of capistrano

After Leadformance/Bridge2#3768, Jarvis couldn't deploy anymore.

The `fog01` `thin.log` outputs the following stacktrace : 

```ruby
127.0.0.1 - - [28/Apr/2014 11:03:20] "GET /deploy/prelive/5b95d9d HTTP/1.1" 200 79 5.8988
From github.com:Leadformance/Bridge2
 * branch            production -> FETCH_HEAD
cap aborted!
Capfile locked at 3.2.1, but 3.1.0 is loaded
/home/deployer/.rvm/gems/ruby-1.9.3-p327@bridge-dev/gems/capistrano-3.1.0/lib/capistrano/version_validator.rb:12:in `verify'
/home/deployer/.rvm/gems/ruby-1.9.3-p327@bridge-dev/gems/capistrano-3.1.0/lib/capistrano/dsl.rb:54:in `lock'
config/deploy.rb:1:in `<top (required)>'
/home/deployer/.rvm/gems/ruby-1.9.3-p327@bridge-dev/gems/capistrano-3.1.0/lib/capistrano/setup.rb:14:in `load'
/home/deployer/.rvm/gems/ruby-1.9.3-p327@bridge-dev/gems/capistrano-3.1.0/lib/capistrano/setup.rb:14:in `block (2 levels) in <top (required)>'
/home/deployer/.rvm/gems/ruby-1.9.3-p327@bridge-dev/gems/capistrano-3.1.0/lib/capistrano/application.rb:15:in `run'
/home/deployer/.rvm/gems/ruby-1.9.3-p327@bridge-dev/gems/capistrano-3.1.0/bin/cap:3:in `<top (required)>'
/home/deployer/.rvm/gems/ruby-1.9.3-p327@bridge-dev/bin/cap:23:in `load'
/home/deployer/.rvm/gems/ruby-1.9.3-p327@bridge-dev/bin/cap:23:in `<main>'
Tasks: TOP => prelive
(See full trace by running task with --trace)
```

So we need to run `bundle install` to get the latest gem on fog01.

WDYT @benflex ?