test network incorrectly recreates a fabric network when creating a channel

Doing the following
```
./network.sh up -s couchdb
./network.sh createChannel -c mychannel
```

results in the fabric network being recreated by the createChannel command using levelDB. The reason for this is due to this check in the `createChannel` Function of `network.sh`

```
[[ $len -lt 4 ]] || [[ ! -d "organizations/peerOrganizations" ]] && bringUpNetwork="true" || echo "Network Running Already"
```

as no fabric-tools image now pulled and launched the check that there are less than 4 images running is not correct.

I do have to question as to why does the createChannel attempt to start a network if no network exists ? The paradigm of doing a single action may be better here and just have the up command do it

But as of now it is wrong so a quick fix would be
```
[[ $len -lt 3 ]] || [[ ! -d "organizations/peerOrganizations" ]] && bringUpNetwork="true" || echo "Network Running Already"
```