Automatic merge from submit-queue (batch tested with PRs 49083, 45540, 46862)

update golang version to go1.8
Signed-off-by: sakeven <jc5930@sina.cn>



**What this PR does / why we need it**:

There are some code breaking the compatibility with golang 1.6. Now kubernetes only support golang 1.8.
We need to update golang version check script.

**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes #49082

**Special notes for your reviewer**:

**Release note**:

```
NONE
```