test: Don't block on graph transitions

Improvements in the engine have uncovered some annoying race conditions
which would cause the engine to block between transitions. This is a
test which catches the most obvious file based ones.

This requires inotify to work in the test environment.

test/shell/yaml-change1.sh

@@ -0,0 +1,30 @@
+#!/bin/bash -e
+
+#if env | grep -q -e '^TRAVIS=true$'; then
+#	# inotify doesn't seem to work properly on travis
+#	echo "Travis and Jenkins give wonky results here, skipping test!"
+#	exit
+#fi
+
+if [ -z $timeout ]; then
+	timeout='timeout'
+fi
+
+# set the config file
+cp -a yaml-change1a.yaml /tmp/mgmt/yaml-change.yaml
+$timeout --kill-after=30s 20s ./mgmt run --yaml /tmp/mgmt/yaml-change.yaml --tmp-prefix &
+pid=$!
+sleep 5s	# let it converge
+grep -q 'hello world' /tmp/mgmt/change1	# check contents are correct
+
+cp -a yaml-change1b.yaml /tmp/mgmt/yaml-change.yaml	# change the config file
+sleep 2s	# let it converge
+grep -q 'goodbye world' /tmp/mgmt/change1	# check new contents are correct
+
+cp -a yaml-change1a.yaml /tmp/mgmt/yaml-change.yaml	# change the config file
+sleep 2s	# let it converge
+grep -q 'hello world' /tmp/mgmt/change1	# check contents are correct again
+
+killall -SIGINT mgmt	# send ^C to exit mgmt
+wait $pid	# get exit status
+exit $?