Remove ignored gemrc and --no-ri --no-rdoc

The RVM sandbox isn't picking up the ```gemrc``` in ```/etc/gemrc``` or ```~/.gemrc```. e.g.

```bash
~/src/rvm $ ruby -e "require 'etc'; puts Etc.sysconfdir"                                                                                                                                                           [master][ruby-1.9.3-p392] 
/Users/james/.rvm/rubies/ruby-1.9.3-p392/etc
```

or you could also install rubies via:

```bash
rvm reinstall 1.9.3 -C --sysconfdir=/etc
```

or you could create a ```gemrc``` in the sandbox ```etc```.*

```ruby
# node['rvm']['default_ruby'] has to be the fully ruby including patch 
# level to match the directory name e.g. 2.0.0-p0 not 2.0.0
directory "/usr/local/rvm/rubies/ruby-#{node['rvm']['default_ruby']}/etc" do
  owner   "root"
  group   "rvm"
  mode    "0755"
  action  :create
end

cookbook_file "/usr/local/rvm/rubies/ruby-#{node['rvm']['default_ruby']}/etc/gemrc" do
  source  "gemrc"
  mode    "0755"
end
```