### Please describe the problem.

Cannot set S3 remote to use Infrequently accessed.

### What steps will reproduce the problem?

git annex enableremote <remote> storageclass=STANDARD_IA

### What version of git-annex are you using? On what operating system?

5.20150930 on Arch Linux

### Please provide any additional information below.

[[!format sh """

# Trying with RR
$ git annex enableremote amazon storageclass=REDUCED_REDUNDANCY
enableremote amazon (encryption update) (hybrid cipher with gpg key XXX) ok
(recording state in git...)

$ git annex info amazon                                        
remote: amazon
description: [amazon]
uuid: XXX
trust: semitrusted
cost: 250.0
type: S3
creds: embedded in git repository (gpg encrypted)
bucket: XXX
endpoint: s3.amazonaws.com
port: 80
storage class: ReducedRedundancy
# snip

# Trying with IA
$ git annex enableremote amazon storageclass=STANDARD_IA       
enableremote amazon (encryption update) (hybrid cipher with gpg key XXX) ok
(recording state in git...)

$ git annex info amazon                                 
remote: amazon
description: [amazon]
uuid: XXX
trust: semitrusted
cost: 250.0
type: S3
creds: embedded in git repository (gpg encrypted)
bucket: XXX
endpoint: s3.amazonaws.com
port: 80
storage class: Standard

# End of transcript or log.
"""]]

### Have you had any luck using git-annex before? (Sometimes we get tired of reading bug reports all day and a lil' positive end note does wonders)

I've had great experiences using git annex normally, but the special remotes tend
to get dicey, like here.

> The `STANDARD_IA` docuemntation now includes the necessary version of the
> aws library to support this feature. [[done]] --[[Joey]]
