Add container test

[Lily922]

No description provided.

[k8s-reviewable]

This change is 

[Lily922]

I'm not sure if this test is designed correctly, you can just think of it as a sample.

[feiskyer]

@LilyFaFa Thanks very much. Please refer docker fake client for adding a fakeClient. Generally, it should

• implements client interface (as you already done)
• contain a few set interfaces, e.g. SetContainers, SetImages, so other tests could update the internal state of fakeClient and revisit whether the state is expected after some operations
• list of called interfaces, so that tests could check whether expected interfaces are called

[Lily922]

@feiskyer Thank you for your advice，I have updated the code by referring to the item in the link，this is the new code.

[feiskyer]

@LilyFaFa Thanks. Seems the PR includes some changes already merged. Could you make a rebase toward master?

[Lily922]

@feiskyer Please have a look ,is this time ok?

[feiskyer]

/lgtm

[feiskyer]

@LilyFaFa Thanks a lot