discuss: difference between apiVersion and apiGroup

[fanminshi]

according to api-groups:

The API group is specified in a REST path and in the apiVersion field of a serialized object.

The operator-sdk has a flag --api-group that represents the above specification. But it seems to me that api-group and apiVersion has the same string. We should figure out the distinction between those two and choose which one to use.

ref: #21

[fanminshi]

cc/ @hasbro17 and @hongchaodeng

[hongchaodeng]

Let's follow the Kubernetes convention:

apiVersion: $GROUP_NAME/$VERSION

So it should be --api-version.

[fanminshi]

@hongchaodeng agreed. that is clearer than api-group.

[hasbro17]

Yeah so long as we document the exact format $GROUP_NAME/$VERSION expected by --api-version that should be fine.