s3store: Exclude aws-sdk-go examples from build
These examples are not compatible with old Go versions.
See
@@ -55,7 +55,8 @@ else
fi
# Install the AWS SDK which is explicitly not vendored
-go get -u github.com/aws/aws-sdk-go/...
+go get -u github.com/aws/aws-sdk-go/service/s3
+go get -u github.com/aws/aws-sdk-go/aws/...
# Test all packages which are allowed on all Go versions
go test $packages
