Use correct order of arguments to assertEqual

The correct order of arguments to assertEqual that is expected by
testtools is (expected, observed).

This patch fixes the inverted usage of arguments in some places
that have cropped up since the last fix of this bug.

Change-Id: Ifbc5da5cba0c8dcdf5b9c9eb6e6bfb1b1c2b49b0
Closes-Bug: #1259292
Remove unused arguments for stack-preview command

--create-timeout/--timeout and --disable-rollback have no meaning in the
context of stack-preview, and actually are not used by Heat during
stack preview action, so remove them.

Change-Id: I1f991eaddf98b0e5c0c3f8b4aaa33947eba53664
Closes-Bug: #1297748
Merge "Use correct order of arguments to assertEqual"
Merge "Remove unused arguments for stack-preview command"