Rework regexes

Hi,

This fixes issue #18 - instead of hard-replacing a string with the url in it, we now match the known last part of the url in a regex and strip that. Also added a spec for specifically that issue (in get_organisations) and rane a rake test;

53 runs, 64 assertions, 0 failures, 0 errors, 0 skips

Edit: Sorry bout the extra commits, forgot to rebase :doh:, but the diff is correct