The password and username has to be passed to the others instances and used

so that build will not fail if the directory was left during previous
builds.

  Using ServerAliases %{SERVER_NAME} would not cause a change of URL to something
  diferent them it was requested.

  A nicer form

because the recent version of paramiko (>= 2.0.0), that is a part of
slapos.toolbox's dependencies, depends on cryptography insead of
pycrypto.

Desactivate testing temporary.

This reverts commit 5656363a.