gems.pp: Unrecognised escape sequence \Q \E

Since the bash script is in double quotes (`"`) the `\Q` and `\E` are interpreted by puppet. Should use single quotes or double-escape?

When applying:
```
Warning: Unrecognised escape sequence '\Q' in file /puppet/puppet-packages/modules/ruby/manifests/gems.pp at line 7
Warning: Unrecognised escape sequence '\E' in file /puppet/puppet-packages/modules/ruby/manifests/gems.pp at line 7
```