installation: update many pypi packages

I made some updates and more importantly documented which ones were failing with a new version.

* Updates alembic to 0.6.5.
* Updates celery to 3.1.13.
* Updates Cerberus to 0.7.0 and comments that 0.7.1 will fail.
* Updates Flask-Cache to 0.13.
* Comment Flask-OAuth>=0.5 to be known to fail.
* Updates inibitset to 2.1.
* Updates msgpack-python to 0.4.
* Updates numpy to 1.8.1.
* Comments pyparsing 2.0.2 to be known to fail.
* Updates PyLD to 0.6.
* Updates raven to 5.0.0.
* Updates rdflib to 4.1.2.
* Updates reportlab to 3.1.
* Updates requests to 2.3.
* Comments SQLAlchemy-Utils >0.24 to be depending on SQLAlchemy>=0.9.3.
* Updates wtforms-alchemy to 0.12.8
* Updates WTForms-Components to 0.9.5
When Travis is running, it will always pick the latest matching one; while locally you may be using older version if you don't do the updates yourself. Pushing the version towards the latest ones ensures that the testing environment matches the production one, in a way. Who's gonna guarantee that it's still working with that older release? (Regarding httpretty, there is not big changes)

If you end up installing invenio in a fresh virtualenv at each release, you will for sure be as up to date as Travis is.