Don't expose X-Auth-Token in heat CLI

Heat CLI exposes X-Auth-Token in debug mode. This patch replaces
X-Auth-Token's value with '{SHA1}<sha1oftoken>'. Some credentials
are exposed by keystoneclient as heatclient uses keystoneclient to
authenticate, it will be fixed in bug:100414.

Change-Id: Ic768af5a947535807ba449fb0aeb1eb98dac56e6
Partial-Bug: #1327019
Merge "Don't expose X-Auth-Token in heat CLI"