acu175507 - Add support for :connection_verify_mode

If :connection_ca_file one provides cannot be verified, the gem raises an SSL auth error.
To workaround the problem one can provide :connection_verify_mode = OpenSSL::SSL::VERIFY_NONE
so that it will work even with unverified certificate.
Merge pull request #13 from rightscale/nextgenKD_acu175507_Do_not_reuse_SSL_connections_wneh_it_is_not_safe

acu175507 - Add support for :connection_verify_mode