using numpy.linalg.svd instead scipy

Hello,

There is SVD implementation in numpy.linalg (http://docs.scipy.org/doc/numpy/reference/generated/numpy.linalg.svd.html) too which can serve the purpose for the LSA algorithm.  I was recently trying to setup scipy on an aws image and was having hard time fixing issues with dependencies, whereas getting numpy to work has been a relatively easier process.

Shantanu