add firewalld to debian Install Dependencies

When install kimchi deb package on Ubuntu14.04, it report firewalld is
required, but it is not installed.

This Ubuntu14.04 is a fresh OS, I install the Dependencies according to
README.md

But README.md misses firewalld.

Signed-off-by: ShaoHe Feng <shaohef@linux.vnet.ibm.com>