Fix build break due to accidental inclusion

The 'cop' service in the docker compose was commented out
during local tests but shouldn't have been checked in.

Change-Id: I57559729eb99f6659855f95f0010d65a97270654
Signed-off-by: Jim Zhang <jzhang@us.ibm.com>

test/fixtures/docker-compose.yml

@@ -2,12 +2,12 @@ version: '2.0'
 
 services:
 
-#  cop:
-#    image: hyperledger/fabric-ca
-#    ports:
-#      - "7054:7054"
-#    command: sh -c 'fabric-ca server start -ca /.fabric-ca/ec.pem -ca-key /.fabric-ca/ec-key.pem -config /etc/hyperledger/fabric-ca/server-config.json -address "0.0.0.0"'
-#    container_name: ca
+ ca:
+   image: hyperledger/fabric-ca
+   ports:
+     - "7054:7054"
+   command: sh -c 'fabric-ca server start -ca /.fabric-ca/ec.pem -ca-key /.fabric-ca/ec-key.pem -config /etc/hyperledger/fabric-ca/server-config.json -address "0.0.0.0"'
+   container_name: ca
 
   orderer:
     image: hyperledger/fabric-orderer