add httpretty as a test dependency

Signed-off-by: Alfredo Deza <alfredo.deza@inktank.com>
remove requests, use boto directly

Signed-off-by: Alfredo Deza <alfredo.deza@inktank.com>
test the new boto request ensuring our urls are kept

Signed-off-by: Alfredo Deza <alfredo.deza@inktank.com>