[python-fuelclient] New CLI 'fuel2 graph upload' command doesn't take into account required args

[Vitalii Kulanov]

Detailed bug description:
New CLI 'fuel2 graph upload' command doesn't take into account required args (-e ENV | -r RELEASE | -p PLUGIN).
If we try to execute command:
  [root@fuel ~]# fuel2 graph upload --file new_graph.yaml
  Deployment graph was uploaded from new_graph.yaml

Steps to reproduce:
1. Deploy Fuel (e.g. 1 master + 5 nodes).
2. Create new env.
3. Create some empty file (new_graph.yaml).
4. Try to upload new_graph.yaml with omitted required args (-e ENV | -r RELEASE | -p PLUGIN).

Expected results:
 fuel2 graph upload: error: one of the arguments -e/--env -r/--release -p/--plugin is required

Actual result:
 Deployment graph was uploaded from new_graph.yaml

Reproducibility:
 Always

Description of the environment:
cat /etc/fuel_build_id:
 206
cat /etc/fuel_build_number:
 206
cat /etc/fuel_release:
 10.0
cat /etc/fuel_openstack_version:
 newton-10.0

Additional information:
Here is a brief command usage example:
[root@fuel ~]# fuel2 graph upload --file
usage: fuel2 graph upload [-h] [-e ENV | -r RELEASE | -p PLUGIN] [-t TYPE] -f
                          FILE
fuel2 graph upload: error: argument -f/--file: expected one argument
Mutually exclusive group [-e ENV | -r RELEASE | -p PLUGIN] erroneously marked as not required.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/323809

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/323809
Committed: https://git.openstack.org/cgit/openstack/python-fuelclient/commit/?id=81cb49df72a3ae3571b52e38fcb0ad2eae809c85
Submitter: Jenkins
Branch: master

commit 81cb49df72a3ae3571b52e38fcb0ad2eae809c85
Author: tivaliy <email address hidden>
Date: Wed Jun 1 14:30:45 2016 +0300

    Align required args for 'fuel2 graph upload'

    Dissallow 'fuel2 graph uplod' command execution without
    required args (-e ENV | -r RELEASE | -p PLUGIN), e.g.:
      usage: fuel2 graph upload [-h]
             (-e ENV | -r RELEASE | -p PLUGIN) [-t TYPE] -f FILE

    Change-Id: I4fb1215874a849ea032afadb9604fca0dc0784a1
    Closes-Bug: 1587837