ibm-storage: update version number and history
ibm-storage: update version number and history

Update the driver version number to 2.1.0 and add version history

Change-Id: I486f7e481faa6502b2d9924243bfe9595ef5a5ac

j-griffith/cinder,openstack/cinder,eharney/cinder,eharney/cinder,phenoxim/cinder,phenoxim/cinder,Datera/cinder,j-griffith/cinder,mahak/cinder,Datera/cinder,openstack/cinder,mahak/cinder