use options to add ca_certs to http_client
Merge pull request #73 from jondruse/master

use options to add ca_certs to http_client
Need to special case for http code 412
Fix test failure
Merge pull request #77 from estately/http_error_412

Need to special case for http code 412
Merge remote-tracking branch 'origin/master' into handle_missing_rets_resources