first steps towards a groups search

There's still no search entry. But now /search/a will find you animals.
update Gemfile.lock for new debugger

the old debugger did not support the current ruby version.
working search entry using name param

Now there are two ways of searching groups that have not been unified:
 - submit the search form - this will POST to /groups/directory/search
   and include the search term in the name param
 - request /groups/directory/search/term ... this will include the term in
   the path and also find the corresponding groups.

We probably want to add some js to use the second method when submitting the form.
But for now this is the most simple thing that could possibly work.
Merge pull request #51 from azul/feature/search_groups

Feature/search groups