maxscale-system-test changed in order to control test environment by itself.
Every test checks which machines are running, compare with list of needed machines
and start new VMs is they are missing in the running machines list.
Tests are executiong MDBCI commands, MDBCI executable should be in the PATH
The test now skips execution of inserts to separate nodes. This should
guarantee that the nodes are synced at all times.
The test now does the inserts and selects inside a transaction to force
the reads to the same node where the inserts are done.
