Default Workflow engine - We should only catch exceptions from action.execute()

[Vincent Françoise]

 In watcher/applier/workflow_engine/default.py, we are checking the return value of action.execute(). As the "TODO" above indicates it (line 118), we should get rid of this and only flag an action as failed if an exception was raised during its execute().

We will also probably need to update the related unit tests.

[Tin Lam (lamt)]

https://review.openstack.org/#/c/284541/

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/284541
Committed: https://git.openstack.org/cgit/openstack/watcher/commit/?id=d7f4f4277282173a534b4e4ac99dd9b99e739f9a
Submitter: Jenkins
Branch: master

commit d7f4f4277282173a534b4e4ac99dd9b99e739f9a
Author: Tin Lam <email address hidden>
Date: Wed Feb 24 23:23:30 2016 -0600

    Remove true/false return from action.execute()

    In watcher/applier/workflow_engine/default.py, we are checking the
    return value of action.execute(). As the "TODO" above indicates it
    (line 118), we should get rid of this and only flag an action as
    failed if an exception was raised during its execute(). We will
    need to update the related unit tests.

    Change-Id: Ia8ff7abd9994c3504e733ccd1d629cafe9d4b839
    Closes-Bug: #1548383