Add Fog::AWS::STS.Mock#assume_role

[pedrommonteiro]

Add Fog::AWS::STS.Mock#assume_role. The method returns a Excon::Response instance mocking the following fields:

• Arn
• AssumedRoleId
• AccessKeyId
• SecretAccessKey
• SessionToken
• Expiration
• RequestId

[lanej]

Thanks @pedrommonteiro

Note: The response presentation of this endpoint has changed significantly http://docs.aws.amazon.com/STS/latest/APIReference/API_AssumeRole.html

[geemus]

Thanks!