Add pktgen traffic profile

Add pktgen traffic profile

This new profile is based on the DPDK pktgen traffic generator. The traffic
generator is controlled using LUA [1]. Those string commands are sent to
the traffic generator using an open socket. Host address and open port are
needed parameters.

The following actions are implemented:
  - start injection
  - stop injection
  - change injection rate
  - clear all stats
  - help message command

[1] http://pktgen-dpdk.readthedocs.io/en/latest/lua.html

JIRA: YARDSTICK-1345

Change-Id: I560a168d194cedc9fdba312ec84437933efc8d9b
Signed-off-by: Rodolfo Alonso Hernandez <rodolfo.alonso.hernandez@intel.com>