[DOC] Update the manual installation guide to rectify errors
[DOC] Update the manual installation guide to rectify errors

By following the present installation guide we are getting errors
So In this patch I have updated to get successful installation

Change-Id: I719a641c5a8d9b12364d6b9b0ac435199ce03f7a
Closes-Bug: #1610950
Closes-Bug: #1604228

zeinsteinz/tacker,zeinsteinz/tacker,openstack/tacker,openstack/tacker,stackforge/tacker,stackforge/tacker,openstack/tacker