Add go lang client test

There is just only one test case for multipart upload in order to
assert Content-MD5 of Complete Multipart Response.
Add client test of go lang to root Makefile
Align the option name with upstream's s3gof3r change

--without-ssl -> --no-ssl

https://github.com/rlmcpherson/s3gof3r/commit/06a28aaeb431d162061556793bfb690d1d5fe671#diff-ea109317064b3b0efdd1141d8c0bd989R134
Merge pull request #895 from basho/refactor/s3gof3r-client-test

Golang client test with s3gof3r

Reviewed-by: kuenishi