Bugfix:proxy env, ansible multinode support

Bugfix:proxy env, ansible multinode support

JIRA: YARDSTICK-893

- hosts and plays in ansible/nsb_setup.yml refactored
Fixed proxy configuration from env or /etc/environment in nsb_setup.sh
Fixed ansible parameter 'environment: "{{ proxy_env }}"' in:
 - roles for components download.
 - roles for components dependencies install.

Now, you can use ansible to modify all yardstick-standalone hosts at once.
1) Configure http[s]_proxy in
- /etc/environment
or
- env variables
2) Modify ansible/yardstick-install-inventory.ini:
  [jumphost]
  localhost  ansible_connection=local

  [yardstick-standalone]
  yardstick-standalone-node ansible_host=192.168.1.2
  yardstick-standalone-node-2 ansible_host=192.168.1.3

  [all:vars]
  ansible_user=root
  ansible_pass=root

3) start:
./nsb_setup.sh # for baremetal/sriov
./nsb_setup.sh <path to admin-openrc.sh> #for openstack heat

Change-Id: I167db8bae8303210f21e8ae6f3870ef054bbedce
Signed-off-by: Malanik Jan <janx.malanik@intel.com>