Revert "add statecouchdb to serial package list"

This reverts commit e70cf33.

Change-Id: Ie21a2a428af43102f8f3e248780965606c0ed89a
Signed-off-by: Matthew Sykes <sykesmat@us.ibm.com>

scripts/run-unit-tests.sh

@@ -16,7 +16,6 @@ excluded_packages=(
 # packages that must be run serially
 serial_packages=(
     "github.com/hyperledger/fabric/gossip/..."
-    "github.com/hyperledger/fabric/core/ledger/kvledger/txmgmt/statedb/statecouchdb"
 )
 
 # packages which need to be tested with build tag pkcs11