no intermediate result when metrics is a dictionary

[PurityFan]

Short summary about the issue/question:
When the type of metrics is a dict, there is no intermediate result. The final result use "default" key to show the result, and what about the intermediate result? Shouldn't these two be consistent?

Brief what process you are following:
Start an experiment and use the "dict" type metrics. For example:
result =
{
"default": 60.65,
"loss": 1.138
}
Then, we can see the point of the final result, can not see the intermediate result, like these:

How to reproduce it:

Start an experiment and use the "dict" type metrics.

nni Environment:

• nni version: 0.5.2
• nni mode(local|pai|remote): pai
• OS: Ubuntu
• python version: 3.5.2
• is conda or virtualenv used?: no
• is running in docker?: yes

Anything else we need to know: