Junqiu Zheng

Suggestion: Use Builder pattern for inputting parameters of Ali-cloud

4

For example, the current way to create a new node of Ali-cloud is: ``` alicloud, _ := gocloud.CloudProvider(gocloud.Aliprovider) create := map[string]interface{}{ "RegionId": "cn-qingdao", "ImageId": "centos_7_04_64_20G_alibase_201701015.vhd", "InstanceType": "ecs.xn4.small", "SecurityGroupId": "sg-m5egbo9s5xb21kpu6nk2", }...