Update 'extras_require' dependencies

[thijs]

The Google App Engine adapter, and the possible upcoming SQLAlchemy adapter, should be added to pyamf/trunk/setup.py:

extras_require={
        'wsgi': ['wsgiref'],
        'twisted': ['Twisted>=2.5.0'],
        'django': ['Django>=0.96'],
        'google': ['GoogleAppEngine>=1.0'],
        'sqlalchemy': ['SQLAlchemy>=0.4']
},

[nick]

Google App Engine isn't part of the setuptools/distutils/pypi distribution so shouldn't be included in the list

[thijs]

Ticket blocked by #277 (SQLAlchemy Adapter)

[mvtellingen]

most likely you only want to load the sqlalchemy adapter if sqlalchemy is installed, thus not making it a requirement ?

[thijs]

Replying to mvtellingen:

most likely you only want to load the sqlalchemy adapter if sqlalchemy is installed, thus not making it a requirement ?

True, that's why it's a 'extras' requirement, which isn't used for anything (yet), it's more an indication that our library supports those third-party libraries like Twisted, Django etc.