fixed the spartan.array dot product with vector bug.
deprecate logging in dot mapper
fix the bug in a better way.
Merge branch 'master' of github.com:spartan-array/spartan
add sparse svd
Merge pull request #109 from MaggieQi/master

add NAS Conjugate Gradient benchmark and naive bayes
use np.linalg.eig instead of our own.
fixed the indentation
Merge pull request #110 from EasonLiao/master

add svd using lanczos method
fix some codes in the tests (cholesky and conj_gradient)