bug of state transition in nnimanager

[QuanluZhang]

Short summary about the issue/question: when there is a error from training service, the error is catched by nnimanager which changes the state to ERROR. But other procedures are still working, so ERROR could be changed to other states later.

Brief what process you are following: running experiments on pai

How to reproduce it: when there is a submission failure, and tuner sends NO_MORE_TRIAL then.

nni Environment:

• nni version: v0.6
• nni mode(local|pai|remote): pai
• OS: ubuntu 16.04
• python version: 3.5
• is conda or virtualenv used?: no
• is running in docker?: no

need to update document(yes/no): no

Anything else we need to know: no