Fix eight typos on Rally document

[Atsushi SAKAI]

Fix eight typos on Rally document (it affects 5 files)

optinal => optional
   https://rally.readthedocs.org/en/latest/feature_request/launch_specific_benchmark.html

behaviour => behavior
natigate => navigate
  https://rally.readthedocs.org/en/latest/release_notes/latest.html

Fuctional => Functional
directiry => directory
automaticaly => automatically
  https://rally.readthedocs.org/en/latest/contribute.html

nessesary => necessary
  https://rally.readthedocs.org/en/latest/plugins.html

Relase => Release
  https://rally.readthedocs.org/en/latest/project_info.html

$ git diff | diffstat
 feature_request/launch_specific_benchmark.rst | 2 +-
 release_notes/latest.rst | 4 ++--
 source/contribute.rst | 6 +++---
 source/plugins.rst | 2 +-
 source/project_info.rst | 2 +-
 5 files changed, 8 insertions(+), 8 deletions(-)

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/205409

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/205409
Committed: https://git.openstack.org/cgit/openstack/rally/commit/?id=3e4467c38b7649601d6b1b415e468ed3adacef0d
Submitter: Jenkins
Branch: master

commit 3e4467c38b7649601d6b1b415e468ed3adacef0d
Author: Atsushi SAKAI <email address hidden>
Date: Fri Jul 24 16:03:09 2015 +0900

    Fix eight typos on Rally documentation

    It affects five files.
    optinal => optional
       https://rally.readthedocs.org/en/latest/feature_request/launch_specific_benchmark.html
    behaviour => behavior
    natigate => navigate
      https://rally.readthedocs.org/en/latest/release_notes/latest.html
    Fuctional => Functional
    directiry => directory
    automaticaly => automatically
      https://rally.readthedocs.org/en/latest/contribute.html
    nessesary => necessary
      https://rally.readthedocs.org/en/latest/plugins.html
    Relase => Release
      https://rally.readthedocs.org/en/latest/project_info.html

    Change-Id: Ia939b2a5efb6cec63365ba8d71db1b31d827835c
    Closes-Bug: #1477849