Add slave interfaces to bond master after bond was created/set up

This workaround is required until salt with the patch [1] is not
used.

- use 'ifenslave' tool to enslave necessary interfaces only if bond
  interface has been changed
- install package that provides 'ifenslave' tool

[1] https://github.com/saltstack/salt/pull/39912

Change-Id: I65b607f26cf7319efb60f154951855d1334e1640
2 files changed