The leap tooling was attempting to run `set_upgrade_vars` at point where
specific upgrade variables were already needed. Within this change that
function call is moved up a few lines so that it has the chance to set
the required values. Additionally the option to pre-define the variable
CODE_UPGRADE_FROM has been added giving the deployer the option to set
this variable before a leap upgrade is run.
Change-Id: I2c780eb46dd57e680fc8681824de2fe913824fd9
Signed-off-by: Kevin Carter <kevin.carter@rackspace.com>
e7ea3b56c6