[API] db_manager init doesn't work

[Lin Yang]

$ db_manager init

Traceback (most recent call last):
  File "/usr/local/bin/db_manager", line 10, in <module>
    sys.exit(main())
TypeError: main() takes exactly 1 argument (0 given)
Exception TypeError: TypeError("'NoneType' object is not callable",) in <bound method Client.__del__ of <etcd.client.Client object at 0x7f7f753d9f10>> ignored

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/417556

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/417556
Committed: https://git.openstack.org/cgit/openstack/valence/commit/?id=6e49e5a1fbd6c95abedfb3e5e4f6b215b2f0c205
Submitter: Jenkins
Branch: master

commit 6e49e5a1fbd6c95abedfb3e5e4f6b215b2f0c205
Author: Lin Yang <email address hidden>
Date: Fri Jan 6 15:55:50 2017 -0800

    Fix execute db_manager init failed

    Previously, `db_manager init` command failed because pbr generated
    script will not pass sys.argv as argument to main function. So fix
    it.

    And improve etcd_db.init_etcd_db to make it check whether each
    directory already exists in etcd at first. If it exist and it's not
    directory, delete and re-create it.

    Change-Id: I7d9980e0a1b38d988fe8144d0cbd618ac12f5498
    Closes-Bug: #1654638