Replace "python-heatclient" with "shade" client

Replace "python-heatclient" with "shade" client

Replaced "python-heatclient" with "shade" client. The "python-heatclient"
library is removed from requirements file. "shade" client version 1.22.2
is the required one for OpenStack Pike release.

shade is the recommended client to interact with OpenStack clouds [1]

[1] https://github.com/openstack-infra/shade

JIRA: YARDSTICK-880

Change-Id: Ibbdfc42a543d2d9ed4cf70d78de3de8cbecd0076
Signed-off-by: Rodolfo Alonso Hernandez <rodolfo.alonso.hernandez@intel.com>