systems directory scripts for Centos7

systems directory scripts for Centos7

Installation scripts for Centos7 have been updated with new packages.
Script will install also python3 packages and create python virtual
environment. As a last step DPDK, OVS and QEMU will be compiled. So
after script execution VSPERF should be ready for use.
It is recommended to execute installation script from user account
with password less sudo access. Otherwise python environment
must be copied over from root home directory.
After VSPERF generic Makefile will be created by VSPERF-114, it can
be enhanced to call build script too.

Change-Id: I6ff5d2660af29cf8be134a4cae3b1d7b559892fa
JIRA: VSPERF-93
Signed-off-by: Martin Klozik <martinx.klozik@intel.com>
Signed-off-by: Abdul Halim <abdul.halim@intel.com>
Reviewed-by: Billy O Mahony <billy.o.mahony@intel.com>
Reviewed-by: Brian Castelli <brian.castelli@spirent.com>