Current test setup is too restrictive, allow running a series of executables in different contexts instead (#597)

* Current test setup is too restrictive, allow running a series of executables in different contexts instead

* Split existing tests that test against swarm

test/worker-node/.multinode

@@ -1 +0,0 @@
-worker1

test/worker-node/01manager.sh

@@ -0,0 +1,9 @@
+#!/bin/sh
+
+set -e
+
+cd $(dirname $0)
+. ../util.sh
+current_test=$(basename $(pwd))
+
+docker stack deploy --compose-file=docker-compose.yml test_stack

test/worker-node/02worker1.sh.context

@@ -0,0 +1 @@
+worker1