Run MaxCtrl test suite in the regression test suite

The MaxCtrl test suite is now a part of the regression test suite. The
cluster tests are expected to fail as that is yet to be implemented.

Also fixed the return value of TestConnections::ssh_maxscale.

maxscale-system-test/test_maxctrl.sh

@@ -0,0 +1,70 @@
+#!/bin/bash
+
+# Check branch name
+ref=$(maxscale --version-full 2>&1|grep -o ' - .*'|sed 's/ - //')
+
+if [ -z "$ref" ]
+then
+    echo "Error: No commit ID in --version-full output"
+    exit 1
+fi
+
+if [ ! -d MaxScale ]
+then
+    git clone https://www.github.com/mariadb-corporation/MaxScale.git
+fi
+
+cd MaxScale
+git checkout $ref
+cd maxctrl
+
+cat <<EOF > start_maxscale.sh
+#!/bin/sh
+sudo systemctl start maxscale
+EOF
+
+cat <<EOF >start_double_maxscale.sh
+#!/bin/sh
+exit 1
+EOF
+
+cat <<EOF >stop_maxscale.sh
+#!/bin/sh
+
+sudo systemctl stop maxscale
+
+sudo rm -rf /var/lib/maxscale/*
+sudo rm -rf /var/cache/maxscale/*
+sudo rm -rf /var/run/maxscale/*
+
+if [ -f /tmp/maxadmin.sock ]
+then
+    sudo rm /tmp/maxadmin.sock
+fi
+
+EOF
+
+cat <<EOF >stop_double_maxscale.sh
+#!/bin/sh
+
+sudo systemctl stop maxscale
+
+sudo rm -rf /var/lib/maxscale/*
+sudo rm -rf /var/cache/maxscale/*
+sudo rm -rf /var/run/maxscale/*
+
+if [ -f /tmp/maxadmin.sock ]
+then
+    sudo rm /tmp/maxadmin.sock
+fi
+
+EOF
+
+chmod +x *.sh
+npm i
+
+# Export the value for --basedir where maxscale binaries are located
+export MAXSCALE_DIR=/usr
+./stop_maxscale.sh
+
+npm test