Update aws-sdk-go to v1.27.0

[stefanprodan]

Update to the latest SDK version as it seems that #2664 broke the ECR auth.

[stefanprodan]

The update didn't fixed it, after adding logging this is the error we get (kiam):

2020-01-06T14:00:50.375362066Z ts=2020-01-06T14:00:50.374622922Z caller=aws.go:124 component=aws error="fetching region for AWS" err="EC2MetadataRequestError: failed to get EC2 instance identity document\ncaused by: EC2MetadataError: failed to make EC2Metadata request\n\tstatus code: 404, request id: \ncaused by: request blocked by whitelist-route-regexp \"/latest/meta-data/placement/availability-zone\": /latest/dynamic/instance-identity/document\n"

[2opremio]

Then I think we should roll back #2664

[2opremio]

@stefanprodan can you give that a try?

[stefanprodan]

Simon confirmed that using the old SDK, Flux works with our kiam setup. I think we should find how to use the new SDK not rollback to a deprecated version.

[stefanprodan]

@aackerman are you using IAM Roles for Service Accounts with Flux 1.17 can you confirm that it works?

[aackerman]

@stefanprodan yes the IAM Roles for Service Accounts features are working for me using the docker.io/fluxcd/flux:1.17.0 image.

[stefanprodan]

@2opremio others are reporting that Flux 1.17 works ok with Kiam, my guess is that we're using an older version of Kiam in Weave Cloud that's not compatible with the newer SDK. I think we should merge this PR and deal with Kiam in our cluster.

[stefanprodan]

@2opremio we have a fix, in order to allow Flux to discover the AWS region, Kiam has to be configured with:

--whitelist-route-regexp=/latest/meta-data/placement/availability-zone

[2opremio]

Awesome!!