S3 Upload policy to be used by EC2 API.

C# |
public S3UploadPolicy( string awsAccessKeyId, SecureString awsSecretAccessKey, string bucketName, string prefix, int expireInMinutes )

- awsAccessKeyId (String)
- Access Key Id of the signer of the policy
- awsSecretAccessKey (SecureString)
- Secret Key of the signer of the policy
- bucketName (String)
- Bucket name to upload
- prefix (String)
- Prefix for the object keys
- expireInMinutes (Int32)
- Expire, minutes from now