Minor bug in rum's install docs

[Jorge Vargas]

Hi all, I was installing rum today to test it out against a
semi-complex db I'm working on.

I was lazy and copied the following string:

easy_install -i http://pypi.toscawidgets.org/rum/0.1/index Rum RumAlchemy tw.rum

and got
error: Could not find suitable distribution for Requirement.parse('Rum')

which means the package is called rum not Rum :)