test_result_server: fixes for running upstream
test_result_server: fixes for running upstream

* No longer requires AWS credentials to be passed in the environment.
  Now, if the environment variables are not set, it falls back to
  boto defaults (which reads ~/.boto.cfg)
* Enables autocommit mode in MySQL. For some reason, the version of
  the MySQL client running in the new environment doesn't enable
  autocommit by default.

This is the version currently running on http://dist-test.cloudera.org:8080/
and I verified that, with the autocommit fix, it's now properly collecting
rows into the database.

Change-Id: I96e653f186578ecf1eb5d7da54f27db2a0fdaba2
Reviewed-on: http://gerrit.cloudera.org:8080/1531
Tested-by: Todd Lipcon <2c763d726a8c2f6afda9be7e0e56a2caa6bb5e6b@cloudera.com>
Reviewed-by: Dan Burkert <2591e5f46f28d303f9dc027d475a5c60d8dea17a@danburkert.com>

cloudera/kudu,InspurUSA/kudu,cloudera/kudu,InspurUSA/kudu,andrwng/kudu,helifu/kudu,EvilMcJerkface/kudu,EvilMcJerkface/kudu,EvilMcJerkface/kudu,InspurUSA/kudu,EvilMcJerkface/kudu,EvilMcJerkface/kudu,helifu/kudu,InspurUSA/kudu,andrwng/kudu,cloudera/kudu,helifu/kudu,InspurUSA/kudu,InspurUSA/kudu,InspurUSA/kudu,andrwng/kudu,andrwng/kudu,EvilMcJerkface/kudu,EvilMcJerkface/kudu,helifu/kudu,helifu/kudu,cloudera/kudu,andrwng/kudu,cloudera/kudu,andrwng/kudu,helifu/kudu,helifu/kudu,cloudera/kudu,andrwng/kudu,helifu/kudu,andrwng/kudu,EvilMcJerkface/kudu,InspurUSA/kudu,cloudera/kudu,andrwng/kudu,cloudera/kudu,helifu/kudu,EvilMcJerkface/kudu,InspurUSA/kudu,cloudera/kudu