Code review comment for lp:~niemeyer/goamz/testing-cleanup

Reviewers: mp+145878_code.launchpad.net,

Message:
Please take a look.

Description:
testutil: new package for test clean up

Killed all the repetition in suite_test files, and improved the
implementation of the test HTTP server.

A few test bugs were also fixed on the way.

https://code.launchpad.net/~niemeyer/goamz/testing-cleanup/+merge/145878

(do not edit description out of merge proposal)

Please review this at https://codereview.appspot.com/7232065/

Affected files:
   A [revision details]
   M aws/aws_test.go
   D aws/suite_test.go
   M ec2/ec2.go
   M ec2/ec2_test.go
   M ec2/ec2i_test.go
   M ec2/ec2t_test.go
   M ec2/ec2test/filter.go
   M ec2/ec2test/server.go
   M ec2/sign.go
   D ec2/suite_test.go
   M exp/mturk/mturk.go
   M exp/mturk/mturk_test.go
   D exp/mturk/suite_test.go
   M exp/sdb/sdb.go
   M exp/sdb/sdb_test.go
   D exp/sdb/suite_test.go
   M exp/sns/sns_test.go
   D exp/sns/suite_test.go
   M iam/iam_test.go
   M iam/iami_test.go
   D iam/suite_test.go
   M s3/s3.go
   M s3/s3_test.go
   M s3/s3i_test.go
   D s3/suite_test.go
   A testutil/http.go
   A testutil/suite.go