When using Keystone auth for software cli, only user with 'admin' role
is allowed to run any commands. When using software cli without 'sudo',
all software commands require user with 'admin' role.
This review also update the exception handling and error reporting.
Test Plan:
PASS: A Keystone user in the 'admin' project with 'admin' role should
be able to run ALL 'software' commands WITHOUT SUDO
PASS: A Keystone user in the 'admin' project with only 'member' and/or
'reader' role should NOT be able to run ANY 'software' commands
WITHOUT SUDO
Story: 2010676
Task: 49754
Change-Id: I46653021b1a82bccded5eb870dc0907cd5c2351b
Signed-off-by: Joseph Vazhappilly <joseph.vazhappillypaily@windriver.com>