pymysql missing from requirements

[Thomas Maddox]

Got the following error when setting up the Craton API test container:

  File "/craton/lib/python3.5/site-packages/craton/db/sqlalchemy/alembic/env.py", line 66, in <module>
    run_migrations_online()
  File "/craton/lib/python3.5/site-packages/craton/db/sqlalchemy/alembic/env.py", line 55, in run_migrations_online
    engine = sa_api.get_engine()
  File "/craton/lib/python3.5/site-packages/craton/db/sqlalchemy/api.py", line 42, in get_engine
    facade = _create_facade_lazily()
  File "/craton/lib/python3.5/site-packages/craton/db/sqlalchemy/api.py", line 37, in _create_facade_lazily
    _FACADE = session.EngineFacade.from_config(cfg.CONF)
  File "/craton/lib/python3.5/site-packages/oslo_db/sqlalchemy/enginefacade.py", line 1241, in from_config
    expire_on_commit=expire_on_commit, _conf=conf)
  File "/craton/lib/python3.5/site-packages/oslo_db/sqlalchemy/enginefacade.py", line 1162, in __init__
    slave_connection=slave_connection)
  File "/craton/lib/python3.5/site-packages/oslo_db/sqlalchemy/enginefacade.py", line 403, in _start
    engine_args, maker_args)
  File "/craton/lib/python3.5/site-packages/oslo_db/sqlalchemy/enginefacade.py", line 427, in _setup_for_connection
    sql_connection=sql_connection, **engine_kwargs)
  File "/craton/lib/python3.5/site-packages/oslo_db/sqlalchemy/engines.py", line 134, in create_engine
    engine = sqlalchemy.create_engine(url, **engine_args)
  File "/craton/lib/python3.5/site-packages/sqlalchemy/engine/__init__.py", line 386, in create_engine
    return strategy.create(*args, **kwargs)
  File "/craton/lib/python3.5/site-packages/sqlalchemy/engine/strategies.py", line 75, in create
    dbapi = dialect_cls.dbapi(**dbapi_args)
  File "/craton/lib/python3.5/site-packages/sqlalchemy/dialects/mysql/pymysql.py", line 49, in dbapi
    return __import__('pymysql')
ImportError: No module named 'pymysql'

Looks to be because the default got changed to using pymysql here: https://review.openstack.org/#/c/436915/, but pymysql never got added as a requirement to the project.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/436963

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/436963
Committed: https://git.openstack.org/cgit/openstack/craton/commit/?id=47ea14c8c9f766f58379e1154deb0f2fc87aae5b
Submitter: Jenkins
Branch: master

commit 47ea14c8c9f766f58379e1154deb0f2fc87aae5b
Author: Thomas Maddox <email address hidden>
Date: Wed Feb 22 14:56:48 2017 +0000

    Add PyMySQL to project requirements

    This patch adds "PyMySQL>=0.7.6 # MIT License",
    according to the OpenStack global requirements,
    to the project's requirements to afford for the
    default SQLAlchemy configuration for the project.

    Change-Id: I779b0cca305638c2e0c24702f8ad464982d541e3
    Closes-Bug: 1666930