bad content-md5 test

[reiddraper]

Add some kind of integration test for #596.

[reiddraper]

S3 returns the expected md5, right now we don't. Here's what s3 returns:

<?xml version="1.0" encoding="UTF-8"?>
<Error><Code>BadDigest</Code><Message>The Content-MD5 you specified did not match what we received.</Message><ExpectedDigest>zBA3KsgMZYMzYik/FJMNUQ==</ExpectedDigest><CalculatedDigest>JiG8gtQrkr0ev1LjqN3e8Q==</CalculatedDigest><RequestId>B2B0B8B365F72EF0</RequestId><HostId>XtSm9vb7QrAIV1H4jIemq+FtjiD+u33CuDHqdsCPo/HnTWI+/ztFL1vmdHCuwiOC</HostId></Error>

Here's what we return for the same request:

<?xml version="1.0" encoding="UTF-8"?><Error><Code>InvalidDigest</Code><Message>The Content-MD5 you specified was invalid.</Message><Content-MD5>zBA3KsgMZYMzYik/FJMNUQ==</Content-MD5><HostId>host-id</HostId></Error>

They both get raised as S3ResponseError: S3ResponseError: 400 Bad Request exceptions in Boto.

[reiddraper]

This also makes Riak CS print out the following crash report:

(riak-cs@127.0.0.1)1> 13:53:06.102 [error] gen_fsm <0.9327.0> in state all_received terminated with reason: invalid_digest
13:53:06.102 [error] CRASH REPORT Process <0.9327.0> with 0 neighbours exited with reason: invalid_digest in gen_fsm:terminate/7 line 611
13:53:06.102 [error] Supervisor riak_cs_put_fsm_sup had child undefined started with {riak_cs_put_fsm,start_link,undefined} at <0.9327.0> exit with reason invalid_digest in context child_terminated

[reiddraper]

Re-opening again release/1.4.