Support Fabric v3

The preview release is available: https://github.com/hyperledger/fabric/releases/tag/v3.0.0-preview

Starting from v3 it requires the following capabilities:

```
interface CapabilitiesV_3 {
  application: "V2_5";
  channel: "V3_0";
  orderer: "V2_0";
  isV2: true;
}

```

