Added Image.deprecate, ImageApiMockTest completed, removed ImageApiExpec...

...tTest

What do you think of the format of the ImageApiMockTest?

If it looks good, ill start converting others to a similar format. 
Quick question: do we want the `toString()` or the `name()` here? The contract for `name()` is a little narrower than `toString()`, which could change to be "prettier", I guess?